Archives of Microbiology
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Preprints posted in the last 90 days, ranked by how well they match Archives of Microbiology's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Galani, A.; Antony Venancius, M.; Tumulero, B.; Sipkema, D.; Sousa, D. Z.
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Syngas fermentation by carbon monoxide (CO)-utilising acetogens offers a sustainable route for converting gasified waste materials into value-added chemicals. In this study, we isolated a novel thermophilic CO-utilising bacterium, strain AZ2, from marine hydrothermal sediment collected on the island of Sao Miguel, Azores, Portugal. Strain AZ2 is an obligately anaerobic, spore-forming bacterium. Average nucleotide identity (ANI; 78.4-86.7%) and digital DNA-DNA hybridization (dDDH; 23.4-32.5 %) analyses indicate that strain AZ2 represents a novel species within a previously uncharacterised lineage represented by the GTDB placeholder genus UBA2545 in the Neomoorellaceae family. Strain AZ2 was able to grow fermentatively on CO, producing acetate. We further demonstrated that its closest isolated relatives - Thermanaeromonas toyohensis, T. burensis, and Thermanaeromonas sp. strain 9S - are capable of growing on CO, producing either acetate or hydrogen gas (H2). Additionally, we unveiled the genomic potential for CO utilisation within other members of the GTDB placeholder class DSM-521 (previously Moorellia) to which our isolate belongs, expanding the list of possible thermophilic CO-utilising acetogens. We propose that strain AZ2T represents the type strain of a novel genus and species, named Thermobium azorense gen. nov., sp. nov. (= DSM 121889T = JCM 39698T).
Mitsumasu, S.; Kasuga, Y.; Nagano, T.; Kumar, V.; Hasegawa, Y.; Maeda, T.; Takasuka, T. E.
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A challenge in using plant biomass is its highly recalcitrant nature, which makes it economically infeasible to utilize. In natural environments, various microbes, including bacteria and fungi, are reported to decompose plant cell wall materials such as cellulose and hemicellulose, and there may be undescribed microbes that contribute to the degradation of plant biomass. We focused on isolating novel plant biomass-degrading bacteria and screened more than 100 isolates from the Tomakomai experimental forest in Hokkaido, Japan. Among them, one novel Bacillus species was chosen for whole-genome sequencing. Comparative genomics and a carbon source utilization assay indicated that the isolate belongs to a subspecies of Bacillus subtilis, which we named B. sp. TTS1. Glucose, cellobiose, xylose, xylan, mannose, or mannan was used as the sole carbon source in the minimum medium, and the growth of this bacterium was determined. Furthermore, a proteomic analysis of B. sp. TTS1 was performed using culture supernatants from various polysaccharide-containing media. In the present study, several key enzymes involved in plant biomass degradation were identified, namely {beta}-1,4-mannanase and xylanase, and they were highly enriched in all tested polysaccharides.
Marshall, M. E. A.; Stott, M. B.; Welford, H. E.; Lagutin, K.; Mitchell, K. A.; Carere, C. R.
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A facultatively anaerobic, hydrogen-oxidizing, thermophilic bacterium (strain KUI-RBT) was isolated from a geothermal spring biofilm in Rotorua, New Zealand. Strain KUI-RBT is a motile, straight rod, measuring approximately 0.7 {micro}m by 1.0 to 1.5 {micro}m with a diderm cell wall. Growth of KUI-RBT occurred from 39 to 74 {degrees}C (Topt 64.5 {degrees}C), pH 5.0 to 7.5 (pHopt 6.5), and 0 to 1% (w/v) NaCl (NaClopt 0.4-0.7%, w/v). KUI-RBT utilizes carbon dioxide and various organic carbon substrates as carbon sources and hydrogen as an electron donor. KUI-RBT can use oxygen (0-21%, v/v), elemental sulfur, thiosulfate, sulfite, nitrate, arsenate, and selenate as terminal electron acceptors. Major fatty acids of strain KUI-RBT include C20:1, C18:1, and C18:0 and the primary quinone is MTK-7. The whole genome G+C content is 34.23 mol%. Phylogenetic analyses indicate KUI-RBT to be a member of the family Hydrogenothermaceae, with Sulfurihydrogenibium azorense Az-Fu1T its closest characterised relative (94.51% 16S rRNA gene sequence similarity, 78.01% whole genome ANI, 61.34% whole genome AAI). Based on phylogenetic and phenotypic analyses, we propose KUI-RBT represents a novel genus and species within the family Hydrogenothermaceae, for which we propose the name Reysenbachia aerophila gen. nov., sp. nov. The type strain is KUI-RBT (=KCTC accession =JCM accession). The GenBank accession number for the 16S rRNA gene sequence of strain KUI-RBT is PZ052650. The GenBank accession number for the whole genome of strain KUI-RBT is JBVODP000000000.
Tang, Y.; Track, A.; Miller, N. A.; Mandelare-Ruiz, P.; Paul, V. J.; Konstantinidis, K. T.; Agarwal, V.
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AO_SCPLOWBSTRACTC_SCPLOWUnderstudied bacterial genera present a dynamic phylogenetic landscape and opportunities for discovering new taxa as more strains are isolated and genomic data is added. Here, through phylogenomic analysis, we describe three novel species of the globally distributed cosmopolitan marine bacterial genus Microbulbifer. This genus is ubiquitous in saltwater microbiomes and is a validated source of biodegradation enzymes as well as high value small molecule natural products. Average nucleotide identity (ANI) to the closest known species, Microbulbifer variabilis ATCC 700307T, was less than 88.4% for all three novel species. Isolates of the three novel species, designated as PAAF003T (T = type strain), ZKSA006T, and SSSA003T were imaged to reveal their phormological characteristics. Based on phylogenetic data, strains PAAF003T, ZKSA006T, and SSSA003T represent three new species of the genus Microbulbifer, for which the names Microbulbifer maximicatervae sp. nov., Microbulbifer regidiadema sp. nov., and Microbulbifer mixtoriginis sp. nov. are proposed, respectively, under the SeqCode. We also reconstructed a robust phylogeny of available Microbulbifer genomes, which should faciliatate future isolation and strain description studies.
Marques, E. d. L. S.; Gross, E.; Jambeiro, I. C. d. A.; Souza, M. C. B.; Dias, J. C. T.; Rezende, R. P.
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From Brazilian limestone caves, we isolated 29 bacteria utilizing phenol (23 bacteria), toluene (all bacteria), and/or benzene (all bacteria) as sole carbon sources. One isolate showed phosphate solubilization, while lipase/esterase activity occurred in two isolates; no amylase activity was detected, but 16 isolates ([~]55%) exhibited protease activity. Among them, Nocardioides sp. SF1 was selected for whole-genome sequencing due to its aromatic compound tolerance and protease activity. Additionally, catechol cleavage assays yielded unexpected purple pigmentation, suggesting non-canonical aromatic metabolism. Its high-quality draft genome (4.25 Mbp, 16 contigs, N50 of 887 kb) lacks canonical phenol hydroxylase but encodes alternative oxidation systems, phenylacetyl-CoA pathway, besides, desferrioxamine siderophore, biosurfactants, and phosphate solubilization, key adaptations for oligotrophic caves and biotechnologically interesting activities. Whole-genome comparisons (TYGS/GGDC, OrthoANI and k-mer) suggest potential new species. Lacks acquired antimicrobial resistance genes (ResFinder) and pathogenicity potential (PathogenFinder). Nocardioides sp. SF1 emerges as a non-pathogenic candidate for aromatic bioremediation and plant growth promotion in contaminated, nutrient-poor environments, highlighting cave actinobacterias unexplored biotechnological potential.
Bastos de Freitas, B.; dos Santos Mendes, M.; Pampuch, M.; Masson, M. L. P.; Lauersen, K. J.
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Here, we describe a filamentous Halospirulina isolate (Halospirulina saudiensis) obtained from water-clay microhabitat the Empty Quarter desert, (ar-Rub al-Kh[a]l[i]), Saudi Arabia which grows in saline conditions. We present its fully sequenced genome, the first for the genus, and characterize its growth dynamics as well as biochemical composition under a range of cultivation conditions. Protein, carbohydrate, lipid, and phycocyanin content varied with cultivation regime but were largely stable. H. saudiensis reached biomass concentrations of up to 9.83 g L-1 at pH 7, 35 {degrees}C and continuous 325 {micro}mol photons m-2 s-1. Variable climate simulations in lab-scale photobioreactors revealed preference for warmer season cultivation under modeled outdoor conditions. Carotenoid analysis revealed a pigment profile enriched in canthaxanthin and other ketocarotenoids, distinguishing it from industrial Limnospira and positioning its value for neutraceuticals and feed additives. Genome analysis identified a carotene ketolase (crtO) homolog consistent with other cyanobacteria that accumulate ketocarotenoids. Phycocyanin content was heavily dependent on culture health and varied with cultivation pH, irradiance, reaching maximum values of 67.3 {+/-} 0.8 mg gDW-1 (6.73 %). Extracted phycocyanin showed marginal thermal stability compared to that from L. platensis. The findings suggest that H. saudiensis could be a promising source of biomass, ketocarotenoids, and natural pigments, cultivated in saline conditions with elevated temperature and irradiance. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=71 SRC="FIGDIR/small/728284v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@17d6143org.highwire.dtl.DTLVardef@7cb1f7org.highwire.dtl.DTLVardef@880df4org.highwire.dtl.DTLVardef@4c16a6_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIHalospirulina saudiensis sp. nov. isolated from Empty Quarter C_LIO_LIFirst genome-resolved characterization of a Halospirulina strain C_LIO_LIReached 9.83 g L-1 in Red Sea salinity conditions C_LIO_LIAccumulates canthaxanthin as major carotenoid C_LIO_LIPhycocyanin slightly thermotolerant C_LI
liu, Y.; Yang, Y.; liu, M.; Chen, S.; cao, H.; Gai, C.; Ye, w.
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Pseudomonas aeruginosa is a clinically significant bacterial pathogen that poses a serious threat to aquaculture. However, there are limited information on Massilia isolates against pathogenic P. aeruginosa in aquaculture. In the present study, a facultative predator, M. varians isolate P2-4, was isolated from aquaculture sediment using Chinese mitten crab Eriocheir sinensis-pathogenic P. aeruginosa as the prey bacterium, and its genomic feature, bacteriolysis-related genes, safety, bacteriolytic spectrum, and in vitro and in vivo antibacterial effects against pathogenic P. aeruginosa in E. sinensis were further characterized. Isolate P2-4 consisted of one chromosome and one plasmid (with a total of 75 tRNAs, 7 5S rRNAs, 7 16S rRNAs, 7 23S rRNAs, 34 sRNAs, 5,238 coding genes, 20 genomic islands, 1 prophage, 23 insertion sequences, and 102 repeat sequences), and harbored 19 bacteriolysis-related genes (pilA, pilB, pilC, pilD, pilF, pilG, pilH, pilM, pilO, pilP, pilQ, pilS, pilR, pilT, mltA, mltB, mltC, mltD, and dacB) associated with cellular motility and cell wall lysis. In addition, the isolate carried no virulence genes, was unable to produce haemolysin, hydrogen sulfide, nitrite and ammonia, and avirulent in E. sinensis with a 7-day acute intraperitoneal LD50 value of above 5.0 x 108 CFU/mL. Furthermore, the isolate possessed a wide bacteriolytic spectrum against pathogenic Shewanella algae, Aeromonas caviae, A. hydrophila, and Photobacterium damselae besides P. aeruginosa, exhibited bacteriolysis rates of 99.35% to 99.99% towards the pathogenic P. aeruginosa at 1.0x103 to 1.0x10{square} CFU/mL, and displayed relative percentage survivals of 42.31% to 73.08% against P. aeruginosa infection in E. sinensis at doses of 6.0 x 103 to 6.0 x 105 CFU/g diet. To our knowledge, this study for the first time demonstrates a M. varians strain as a potential biocontrol agent against pathogenic P. aeruginosa in aquaculture.
Nag, P.; Govindannagari, R.; Prasad, K.; Mounika, T.; Chandran, L. P.; Das, S.; MBB, P. B.; RM, S.
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Plant growth promoting microbes enhance developmental progression of the host by influencing its nutrient availability or by deploying secondary metabolites responsible for manipulating the hormonal crosstalk. Microbacterium bengalense sp. nov. GB16_1_BI (Accession number: SRX9280401), a newly identified ammonium releasing Actinomycetota, could enhance plant growth by manipulating rhizosphere bacteria. Amplicon sequencing of the 16S rRNA V3-V4 region from the rhizosphere of the black rice (Chakhao Poireiton) showed that GB16_1_BI could inhibit most bacteria. However, GB16_1_BI inoculation encouraged the growth of rare bacteria specific to waterlogged rice rhizosphere. Analysis of the OTUs using PICRUSt2 (Phylogenetic investigation of communities by reconstruction of unobserved states) showed increased abundance in the marker genes for nitrogen cycling (nifH, nrfA and nrt) but not for nifD or nifK which was also reflected in the ANOSIM analysis in the OTUs of the N-fixing bacteria. Marker genes for methane metabolism (comA, comB, cofG and cofH) were also more abundant in the inoculated plants than the control; however, ANOSIM studies did not support this observation in the OTUs of methane cycling bacteria. Both Methylosinus and Methylocystis, the two most abundant methanotrophic OTUs, are also known to be nitrogen fixers. Hence, GB16_1_BI could influence plant growth predominantly by manipulating nitrogen cycling microbes. The genome sequence as well as untargeted metabolome analyses of GB16_1_BI showed abundance of secondary metabolites with probable antimicrobial activity. GB16_1_BI could utilize varied carbohydrates and amino acid as energy source and form persister-like cells may help it to survive in the soil in absence of the host plant.
Garcia Otero, P.; Kraft, B.
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Ammonia-oxidizing archaea (AOA) are frequently found in oxygen-depleted marine environments with permanent or temporal presence of sulfide (HS-). However, it remains unexplored how sulfide affects the activity of ammonia-oxidizing archaea. We studied the capability of Nitrosopumilus maritimus SCM1 to oxidize ammonia when exposed to HS-. Ammonia oxidation remained active even after exposure to sulfidic spikes in the lower micromolar range, albeit at reduced rates compared to the absence of HS-. However, 90 {micro}M HS- completely inhibited ammonia oxidation. We found no evidence of NO-dismutation under oxygen depletion and presence of HS- (20 {micro}M): the formation of O2, N2O and N2 did not occur. All in all, we confirmed ammonia oxidation in N. maritimus SCM1 under oxic conditions after sulfide additions, but no evidence of NO-dismutation under sulfidic conditions. Our findings suggest that AOA can recover ammonia-oxidation activity after oxygen re-exposure in regions with periodic sulfide accumulation. However, in permanently sulfidic areas, ammonia oxidation recovery seems unlikely, as NO-dismutation does not appear to be a viable mechanism.
Jiang, F.; Shi, H.; Lu, M.; Zhao, Z.; Xu, X.; Feng, H.
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Petroleum pollution has increased worldwide, driving the search for microorganisms with efficient hydrocarbon-degrading capabilities. Here, we report a novel bacterium, Gordonia sp. B7-2, isolated from mangrove sediments in Hainan, China. Phylogenetic analysis based on the 16S rRNA gene and whole-genome sequences, together with digital DNA-DNA hybridization and average nucleotide identity values, supported its classification as a new species within the genus Gordonia. The complete genome of strain B7-2 consists of a single circular chromosome of 5.39 Mb with a G+C content of 65.99%, and encodes 4,887 protein-coding genes. Genomic annotation revealed a complete pathway for aromatic hydrocarbon degradation, including genes encoding protocatechuate 3,4-dioxygenase and biphenyl-2,3-diol 1,2-dioxygenase, whereas genes involved in the initial oxidation of alkanes were absent. Consistent with these genomic predictions, strain B7-2 degraded 64.33% of crude oil (300 mg/L) within 28 days, with rapid degradation during the initial 14 days, followed by a slower phase thereafter, reflecting the dynamics of complex hydrocarbon mixtures. Together, these results demonstrate that strain B7-2 is specialized for the degradation of aromatic hydrocarbons and highlight its potential for targeted petroleum bioremediation. IMPORTANCEMangrove ecosystems are highly vulnerable to petroleum contamination, yet the microorganisms responsible for hydrocarbon turnover in these environments remain poorly characterized. This study describes a new bacterial species, Gordonia sp. B7-2, that exhibits a strong metabolic specialization for aromatic hydrocarbon degradation. Unlike many known oil-degrading bacteria that preferentially utilize alkanes, strain B7-2 targets aromatic components of crude oil, which are among the most persistent and toxic fractions.Its ability to efficiently degrade crude oil highlights its potential in the bioremediation of contaminated coastal environments and expands our understanding of microbial contributions to hydrocarbon cycling in mangrove sediments
Madsen, P. B.; Hensen, N.; Orsucci, M.; Johannesson, H.
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Background: Human activities such as mining generally lead to increased heavy metal concentrations in the environment. While traditional remediation techniques are often costly, the use of fungi as bioremediators, known as mycoremediation, is increasingly gaining attention as a sustainable approach for removal of heavy metals. Here, we evaluated heavy metal levels inside the Kiirunavaara iron ore mine in Northern Sweden and analysed fungal responses to various metal concentrations by comparing growth and metal uptake in mine-derived isolates and closely related control isolates. Results: Sediments inside the mine were enriched in heavy metals compared to those from the outlet of the mine to natural lakes. Six Fusarium isolates were recovered from contaminated mining environments: five isolates from inside the mine were identified as Fusarium oxysporum, and one isolate from the outlet was identified as Fusarium tricinctum. Isolates from the mine and outlet showed overall higher survival and biomass production in presence of copper, iron, and zinc across a range of concentrations (up to 1000 mg/L) compared to control isolates. At the same time, these isolates often exhibited reduced relative metal uptake. As a result, mycoremediation potential, assessed as total uptake in the grown mycelium, was isolate-dependent. Conclusions: Based on these results, we conclude that Fusarium isolates from the Kiirunavaara mine show increased growth in media enriched with heavy metals compared to closely related control isolates. We additionally show that mycoremediation potential is not necessarily associated with environmental origin. Instead, mycoremediation potential should be evaluated on a case-by-case basis for each isolate and based on specific needs for mycoremediation.
Ramos Cespedes, J.; Castillo Fernandez-Davila, S.; Navarro Segura, R.; Dumet Poma, Y.; Munoz Titto, S.
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In this study, the lipid content produced by Thraustochytrium sp. in a medium prepared from orange pulp residue was compared with that obtained in a conventional medium. The pulp residue was subjected to freezing, blending, and filtration in seawater to prepare three treatments: conventional medium (T1), filtrate (T2), and filtrate supplemented with KNO3 (T3). A growth curve was performed over six days, after which biomass and lipid content were analyzed. The results showed that T2 exhibited the highest cell growth and biomass yield (5.24 g/L). However, lipid content was higher in the conventional medium (38.75%), whereas the treatments containing orange extract showed lower values. These findings suggest that the medium prepared from orange pulp residue is feasible for the growth of Thraustochytrium sp., but requires optimization to enhance lipid accumulation and its potential use in sustainable bioprocesses.
Calapa, K. A.; Bock, R.; Embree, J.; LoBrutto, J.; Embree, M.
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This study investigated the genomic and biochemical characteristics of two amylolytic microbial strains, NATIVEDY160T (= JE7B6T = NRRL B-68523T) and NATIVEDY161T (= JL13D9T, = NRRL B-68524T) isolated from the rumen of healthy Holstein dairy cattle. Both strains are obligately anaerobic, non-motile, Gram positive, catalase-negative, and oxidase-negative. Morphologically, NATIVEDY160T grows in long coccoid chains while NATIVEDY161T grows in short chains or pairs. NATIVEDY160T can catabolize amygdalin, esculin/ferric citrate, and starch, compared to NATIVEDY161T which utilizes amygdalin, arbutin, esculin/ferric citrate, glycogen, and D-maltose as determined by API 50 CH carbon panels. Starch degradation ability was verified for both strains, but neither showed cellulolytic activity as confirmed by starch agar and Congo red agar assays, respectively. HPLC analysis revealed that lactate was the primary end product of both strains carbohydrate fermentation, while strain NATIVEDY161T also produced small amounts of acetate. 16S rRNA sequences from both strains cluster with the Oscillospiraceae (formerly Ruminococcaceae) lineage Ruminococcus species, but average nucleotide identity of either strain compared to closely related Ruminococcus members was under the species threshold (95%). Genomic, phylogenetic, and phenotypic interrogation support NATIVEDY160T and NATIVEDY161T as novel species. Each strain was isolated from the rumen of dairy cows located within the central valley of southern California, which has a rich history of Dutch and Basque dairy farm ownership and is still the case today in the region. In recognition of the contributions and heritage of the central and southern California dairy industry, the names Ruminococcus hollandia and Ruminococcus vasco are proposed with NATIVEDY160T and NATIVEDY161T as their respective type strains.
Khairi, N.; Hamdan, N. H.; Rozaimi, M.; Md Zoqratt, M. Z. H.; Mohammad Nasir, M. A.; Abdella, B.; Tan, G. Y. A.; Eem, L. P.; Amir, A. A.; Akma, W. S.; Hazrin Chong, N. H.
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Microbial communities are central to the biogeochemical cycling of nutrients, critically shaping ecosystem functioning and influencing climate change mitigation. Mangrove ecosystems are among the most important global carbon sinks that enable large amounts of carbon to be sequestered and stored. However, gaps persist in understanding the fundamental aspects of microbial-driven carbon cycling in these environments. This research explores the microbial taxonomic and functional diversity related to carbon cycling in selected tropical mangrove sediments across various locations and depths. Sequencing data analyses based on the 16S rRNA gene revealed distinct microbial community composition but conserved predicted functions across the different mangrove locations. Depth was a strong influence on the functional composition, with carbon-related pathways and metabolic strategies differing between top and bottom sediments. Putative functional gene abundance analyses revealed that carbon fixation processes were among the top carbon-related pathways, suggesting the key role of mangrove microbial communities in sustaining long-term carbon storage. Within these communities, Desulfobacterota appeared as a primary contributor to carbon fixation, while Chloroflexota played a significant role in carbon metabolism and methane cycling. Co-occurrence network analyses also revealed that these microbial groups were among the keystone taxa in mangrove sediments. Our study adds on to the body of knowledge on the mangrove microbiome and their carbon metabolic processes, which helps to improve strategies for managing and leveraging these vital carbon sinks.
Zerin, T.; Bethe, M. I.; Sultana, S.; Aktar, S.; Akter, M.; Masud, A. I.; Osail, S. M.
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Compact poultry raising has turned poultry litter into an environmental problem, as it may all be packed with heavy metals and drug-resistant germs. Of all the metals, chromium contamination not only disturbs the general environment but is also a source of concern for public health. Poultry litters were taken from 14 farms in different places, and the bacteria characters from different places were tested for their capacity to tolerate Cr(VI). A total of 31 bacterial isolates were initially screened, and three of them (AH-2, AZ-1, and AMF-3) appeared to be very resistant to chromium. The isolates were able to survive at the highest concentration, 800 mg/L of the Cr(VI); however, AH-2 was the most resistant one (MIC: 900 mg/L; MBC: 1000 mg/L). Chromium reduction tests showed that AMF-3 at high concentration showed the maximum chromium reduction, while AH-2 achieved higher chromium reduction at medium concentration. Phenotypic and biochemical analysis showed that the isolates were Staphylococcus spp., which was confirmed by 16S rRNA gene sequencing as S. cohnii, S. saprophyticus, and S. gallinarum. Moreover, chromium was detected at higher levels in poultry litter compared to the feed, with the highest accumulation in AZ farm litter (4464.0 {micro}g/kg). The highlighting feature of our article is the presence of chromium-tolerant and reducing bacteria in poultry environments. Besides that, the level of chromium in poultry litter is really high, and it points to the need for better waste management.
Asokan, N.
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One of the effects of the intensified agricultural activities involves environmental pollution by pesticides, which are bound to get into the soil and ultimately into the water sources through leaching. The recurrent exposure of soil microbiota to these poisonous substances facilitates the process of adaptive resistance and catabolic functions. In the current research, bacterial cultures taken in Karuppur and Salem pesticide-contaminated agricultural soils were filtered on their capability to decompose organophosphate pesticides. Two strong isolates, which were referred to as Bacillus sp. and Micrococcus sp. had a great level of tolerance and degradation capacity. Significant biomolecular changes in these isolates were observed after long-term exposure (three months) to organophosphate pesticides. A protein estimation showed a strong rise in the overall total protein content indicating the activation of stress-related and degradative enzymes. Genomic DNA damage was identified by DNA ladder assay, which is a genotoxic stress caused by pesticides. Thus, plasmid profiling also revealed a rise of copy number and change of the size of plasmids, implying potential adaption through plasmids and greater degradation potential. This evidence indicates that long-term exposure to pesticides leads to microbial adaptation in terms of physiological and genetic changes to allow survival in adverse environments. The isolates identified have great potential to be used in bioremediation strategies that will be used in detoxifying the soils that have been contaminated with organophosphate.
Shimabukuro, K.; Miyagi, I.; Harashima, N.
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In many cases, cancer cells develop resistance to chemotherapy and other cancer treatments. Therefore, there is a need for new therapeutic agents using naturally derived compounds that are expected to have low toxicity and fewer side effects. Fucoidan is a sulfated polysaccharide found in brown algae such as kelp and wakame seaweed. Many previous reports have shown that fucoidan exerts anti-bacterial, anti-viral, antioxidant, immunomodulatory effects, and anti-tumor effects. The antitumor and antiviral effects of fucoidan have been reported to vary depending on its origin, as they are influenced by sulfate content and molecular weight. Therefore, it is important to investigate the antitumor effects of various species of fucoidan, but there are few reports on the effects of fucoidan derived from Laminaria japonica on colorectal cancer. In this study, we evaluated the effects of fucoidan from Laminaria japonica on apoptosis in five human colon cancer cells. The apoptotic cell population was significantly increased in fucoidan-treated cells. In addition, the expressions of Bax, Bak, PARP, caspase-8, -9 and -3 were upregulated. The necroptosis-related molecule RIP and MLKL were degraded indicates that necroptosis was not involved in this fucoidan-treated cell death. These results suggest that fucoidan-treated cells showed induction of apoptosis via mitochondrial intrinsic pathway, but not necroptosis via caspase-8. Fucoidan-induced apoptosis may prove useful in the therapeutic protocol of colon cancer.
Dragone, N. B.; Clemens, H.; van Hamelsveld, S.; Weaver, L.; Nazmi, A. R.; Stott, M.
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Geothermal springs are unique environments that harbor diverse populations of microorganisms. As a result of their environmental and geochemical variability, different springs can support distinct heterogeneous communities of organisms with unique functional adaptations and metabolic capabilities. A recent molecular survey of Aotearoa-New Zealand hot springs indicated that these springs may support thermophilic microorganisms be able to degrade plastics. To test this, we applied a cultivation-centered approach via an in situ enrichment of putative plastic-degraders using high surface are polyethylene terephthalate (PET), polylactic acid (PLA), and polyhydroxybutyrate (PHB) substrates in a diversity of New Zealand hot springs. The plastic associated microbial communities were characterized via marker gene and analyses. Finally, plastic-associated biofilms were used as inoculum to isolate thermophilic plastic degraders. Via this process, we confirm that there are plastic degrading bacteria are present in springs across Aotearoa-New Zealand. Moreover, we isolated two PHB degrading strains (Cuprividus sp. and Rubrobacter sp.) and demonstrated their capability to metabolize plastic under thermophilic conditions in vitro. While the pathways identified in our plastic degrading isolates suggest they may be able to metabolize plastics for carbon, the primary use of plastics by geothermal microbial communities does not appear to be as an energy source. Instead, they appear to mainly serve as surfaces for microbial attachment, composed primarily of non-plastic degrading taxa.
Mathew, D.; Bhat, S. G.
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Melanins are biological macromolecule with immense functionality synthesised by a wide spectrum of living organism. It is mainly synthesised by the oxidative polymerization of indolic and phenolic compounds through several enzymatic process. It has wide spread application in agriculture, cosmetic and therapeutic industry due to its various properties including antioxidation ability, UV protection efficiency and anticancer activity. Because of this wide range of application in different sectors, large scale production and commercialization attains enormous consideration. The present study deals with the effect of 12 different process parameters on melanin production viz., production media, incubation time, inoculum concentration, pH, temperature, agitation, carbon source, phosphate and magnesium source, CuSO4.5H2O, sodium chloride and L-tyrosine on melanin production by Pseudomonas stutzeri strain BTCZ 109 obtained from Arabian sea sediments was evaluated. After optimizing the important process parameters, the bacteria showed about ~4.65 fold increase in melanin production compared to unoptimized cultural conditions. The melanin optimized through this method was found to be nano sized. The Nano sized DOPA melanin in treating Skin cancer cell line SK ML28 which showed a dose-dependent activity with an IC50 value of 164 g/mL. All these results highlight the therapeutic efficiency of DOPA melanin Nano particle as promising bioactive molecule.
Song, J.; Yan, Z.; Perez-Moreno, J.; Zhang, F.; Xie, T.; Su, L.; Liu, J.; Wang, Y.; Liu, D.; Shi, X.; Yang, Z.; Yang, C.; Liu, W.; Shi, X.; Wan, S.; Cheewangkoon, R.; Dai, D.; Senanayake, I. C.; Yu, F.
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During mycological surveys in Yunnan Province, China, specimens of a fungus producing massive, upright stromata up to 50 cm high and individually 2.2 Kg in weight were sampled. Through an integrative taxonomic approach combining detailed morphology, multilocus phylogeny (ITS, LSU, RPB2, TUB2), and phylogenomic analyses, this fungus is proposed as the new species Dianjunus rex gen. et sp. nov., the type of the new family Dianjunaceae (Xylariales). Phylogenetic analyses robustly place Dianjunaceae as a distinct sister clade to Graphostromataceae. Divergence time estimation dates the origin of this family to the early Paleocene (~65 Mya), coinciding with the post-K-Pg extinction period, when an estimated 75% of all plant and animal species went extinct, and a significant ecological reorganization of life on earth happened. The stromata of D. rex represent the largest fructifications documented within the Ascomycota, significantly expanding the known morphological range of the Xylariales. The study provides a comprehensive description, including a nodulisporium-like anamorph with periconiella-like branching patterns, and discusses the taxon's phylogenetic placement, and distinctive morphology. This discovery highlights the unexplored fungal diversity in East Asian forests.