Indigenous Strains Research Articles

Modification and mechanistic study of fluid/fluid and carbonate rock/fluid interfaces using a glycolipid biosurfactant from an indigenous strain of Gordonia terrae for MEOR applications

To clarify the mechanism of the interface behavior between carbonate surface/biosurfactant solution/oil systems, the interfacial tension (IFT), surface wettability, spreading coefficient (SC), and capillary number were investigated with regard to the synergistic effects of a biosurfactant from an indigenous Gordonia terrae strain (isolated from an Iranian oil reservoir), formation water salinity, and pH using response surface methodology (RSM-CCD). According to the analysis of variance results, the process effectively depicted by the quadratic model demonstrated statistical significance in terms of the responses of IFT, wettability alteration, and SC, which were significantly affected by biosurfactant concentration. The optimal conditions were 0.260 g/L biosurfactant, 36.202 g/L salinity, and a pH of 5.9. Accordingly, the quadratic model was verified using the estimated optimal parameters, thereby confirming the accuracy of the model in which a strongly water-wet surface (contact angle change from 159° to 31°) and IFT reduction (from 23.96 to 1.26 mN/m) resulted in an SC of near-zero value (−0.18) and 25 % recovery of oil during the imbibition experiments after secondary water flooding. The desorption of the polar components of crude oil from the dolomite rock surface was also investigated through determining the un-coverage ratios of the elements using energy dispersive X-ray microanalysis and characterization. Although the solutions containing biosurfactants contributed to the alteration of the rock surface wettability, their performance strongly depended on the pH and salinity, resulting in different desorption ratios. The desorption of approximately 40 % of the adsorbed organic compounds from the carbonate surface was a critical limiting factor affecting the surface properties of the rock, and was responsible for altering the wettability to water-wet conditions. The results of this study are expected to contribute to the development of effective biosurfactant-flooding techniques for MEOR.

Indigenous Lactic Acid Bacteria as Antioxidant Agents in the Production of Organic Raw Fermented Sausages

The study aimed to assess the impact of lactic acid bacteria (LAB) strains on the antioxidant, physico-chemical properties, and microbiological quality of fermented sausages. Five treatments of raw sausages were prepared: two controls without LAB addition (C, P), and three samples with LAB addition (SCH1, BAL6, KL14). Fatty acid composition, cholesterol content, physico-chemical, microbiological tests, and antioxidant assays, were performed at time 0 and after 1 and 2 months of storage. A significantly higher ability to scavenge free radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl) was found in sausages with all LAB strains. In the case of the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) test, it was noted that KL14 treatment had higher antioxidant activity. The main fatty acids in sausages were monounsaturated and saturated. A significantly lower cholesterol content was observed in sausages with the addition of LAB. Sausages with LAB strains differed significantly in pH value. Water activity decreased significantly during storage. After 2 months of storage, the sausages with BAL6 and KL14 strains were characterized by significantly lower redox potential and a lower TBARS (thiobarbituric acid reactive substances) index. It was found that P sausages had the darkest color. SCH1, BAL6, and KL14 strains were also capable of producing red color. The total number of microorganisms in the sausages was high, which is mainly due to the high LAB content and yeast and mold counts. No spoilage or pathogenic microflora were detected. Indigenous LAB strains have the potential to improve the quality and safety of fermented meat products.

Synergistic bioremediation of petroleum-contaminated soil using immobilized consortium of Rhodococcus rhodochrous and Bacillus subtilis laccase

Petroleum-contaminated soil represents a significant environmental and public health challenge on a global scale. Microbial bioremediation has shown potential, yet the role of enzymes in enhancing petroleum degradation remains underexplored. In this study, the synergistic effects of Rhodococcus rhodochrous (R.rh) and Bacillus subtilis-derived laccase (BsLac) was investigated in the remediation of petroleum-contaminated soil. Immobilized R.rh (PSIMRH) and BsLac (ADIMLac) exhibited higher petroleum degradation rates than their free state, achieving 78.3% and 56.3% degradation in liquid systems, respectively. The combined treatment of PSIMRH and ADIMLac demonstrated a synergistic effect on petroleum degradation, achieving 43.6% with a maximum degradation constant of 0.0335 d−1, representing a 202.7% improvement over untreated soil. PSIMRH enhanced petroleum degradation through microbial metabolism, while ADIMLac accelerated the initial breakdown of complex hydrocarbons into simpler, more bioavailable ones via enzymatic oxidation, providing growth substrates for microbes and significantly improving petroleum degradation rates. The microbial analysis revealed an increase abundance of known petroleum-degrading bacterial genera, including Rhodococcus, Lysobacter, Micromonospora, and Streptomyces. However, the presence of BsLac appeared to reduce the competitive advantage of Rhodococcus, promoting the proliferation of indigenous strains like Lysobacter and Streptomyces. These results suggest that enzyme-microbe synergy can enhance the bioremediation process by altering microbial community dynamics and accelerating petroleum degradation. This study attempts to remediate petroleum-contaminated pollution with the combined use of strains and enzymes, providing a new approach for the remediation of other pollution problems.

Field Demonstration of Indigenous Strains Bacillus thuringiensis and Beauveria bassiana for Sustainable Management of Spodoptera litura in Groundnut

This study by Krishi Vigyan Kendra, Nellore, evaluates the efficacy of biopesticides Bacillus thuringiensis (Bt) and Beauveria bassiana formulations against S. litura compared to conventional insecticides over two growing seasons (2018-19 and 2019-20). Twenty Front Line Demonstrations (FLDs) involving 20 farmers were conducted, with treatments applied when leaf damage exceeded 25%. Results indicated significant reductions in leaf damage (8.40% for biopesticides vs. 8.89% for insecticides) and larval populations. Specifically, larval counts decreased substantially after treatment, with average counts at 50 DAS dropping from 21.29 (FP) to 3.37 (Demo) in 2018-19 and from 22.15 (FP) to 3.53 (Demo) in 2019-20. Economic analysis revealed comparable net returns and benefit-cost ratios for both treatments (1.92 and 1.93 for biopesticides and insecticides, respectively). These findings support the economic viability of adopting biopesticide, promoting sustainable agricultural practices and profitability in groundnut cultivation.

Microbial depolymerization of Kraft lignin for production of Vanillic acid by indigenous ligninolytic strains

Lignin is a potential renewable source for the production of many value-added bio-products through bacterial depolymerization. In this study, Kraft lignin (KL) was depolymerized by indigenous potential ligninolytic strains to obtain the optimum amount of Vanillic acid. Initially, fifteen bacterial strains were isolated from decaying wood mixed soil to assess their lignin degradation efficiency. Five potential lignin-degrading microbes (RW-B2, RW-B4, RW-B9, RW-B11 and RW-B15) were identified by nutrient enrichment technique. RW-B15 was observed as a dominant strain sharing a 99 % resemblance to Bacillus megaterium sp. Optimum temperature and bacterial inoculum concentration were noted as 35 °C and 1 %, respectively. Mixed microbial culture of five potential ligninolytic strains showed better KL degradation than pure culture due to different metabolic capacities, enzymatic mechanisms and synergetic impact among the association members. The KL degradation study was conducted with different KL concentrations (500–2000 mg/l) at optimum temperature using 1 % inoculums. The production of Vanillic acid increased from 60.1 to 199.9 mg/l with increasing concentration of KL from 500 to 2000 mg/l. The maximum production of Vanillic acid was obtained on 3rd day of degradation and it decreased thereafter which is probably due to an increase in microbial toxicity and enzymatic activity. However, the COD level continuously decreased for all KL concentrations with degradation time till the last day. The pH of the KL solution slightly decreased on 3rd day due to the acidic nature of Vanillic acid. GC-MS analysis confirmed the presence of Vanillic acid and showed the presence of other monomeric compounds formed after KL degradation.

Comparison and mechanism study on solidification of loose pisha sandstone by indigenous bacteria and sporosarcina pasteurii

Pisha sandstone is a kind of sandstone which is easy to collapse by water in Shanxi, Shaanxi and Inner Mongolia of China, and suffers from hydraulic erosion all the year round. In recent years, some scholars have used microbial induced calcium carbonate precipitation (MICP) technology to solidify Pisha sandstone to improve the water erosion resistance of Pisha sandstone. However, for the climate environment with low average temperature in Pisha sandstone area, the commonly used Sporosarcina pasteurii are not well adapted. The purpose of this study is to use the indigenous strainsto solidify the loose Pisha sandstone, and to compare the growth adaptability, mechanical properties and water erosion resistance of the solidified layer with Sarcina pasteurii at different temperatures, and to explore the mechanism of different temperatures and strains affecting the microbial solidification of Pisha sandstone from the micro scale. At the same time, a mixed bacterial liquid solidification test was also set up. The results showed that the solidified thickness of indigenous strains was 4.65 % higher than that of Sporosarcina pasteurii, and the thickness and strength of mixed strains were increased by 19.57 % and 36.62 %, respectively. The growth and solidification effect of indigenous strains were less affected by low temperature. Compared with Sporosarcina pasteurii, at low temperature, the bacterial concentration decrease of indigenous strains was reduced by 26.13 %, the thickness loss of solidified layer was reduced by 13.04 %, and the strength loss of solidified layer was reduced by 13.39 %. The effect of low temperature on the growth of bacteria is mainly reflected in affecting the maximum concentration of bacteria and the growth rate. The effect on MICP mainly reflected in affecting the life activities of bacteria and the crystal form and morphology of calcium carbonate. The research results provide a theoretical basis for the MICP technology application of indigenous strains and multi-strains in Pisha sandstone area soil reinforcement and solidification slope.

Rapid screening of indigenous degrading microorganisms for enhancing in-situ bioremediation of organic pollutants-contaminated soil

Organic pollutants (OPs) have caused severe environmental contaminations in the world and aroused wide public concern. Autochthonous bioaugmentation (ABA) is considered a reliable bioremediation approach for OPs contamination. However, the rapid screening of indigenous degrading strains from in-situ environments remains a primary challenge for the practical application of ABA. In this study, 3,5,6-Trichloro-2-pyridinol (TCP, an important intermediate in the synthesis of various pesticides) was selected as the target OPs, and DNA stable isotope probing (DNA-SIP) combined with high-throughput sequencing was employed to explore the rapid screening of indigenous degrading microorganisms. The results of DNA-SIP revealed a significant enrichment of OTU557 (Cupriavidus sp.) in the 13C-TCP-labeled heavy DNA fractions, indicating that it is the key strain involved in TCP metabolism. Subsequently, an indigenous TCP degrader, Cupriavidus sp. JL-1, was rapidly isolated from native soil based on the analysis of the metabolic substrate spectrum of Cupriavidus sp. Furthermore, ABA of strain JL-1 demonstrated higher remediation efficacy and stable survival compared to the exogenous TCP-degrading strain Cupriavidus sp. P2 in in-situ TCP-contaminated soil. This study presents a successful case for the rapid acquisition of indigenous TCP-degrading microorganisms to support ABA as a promising strategy for the in-situ bioremediation of TCP-contaminated soil.

In-vitro & In-vivo Studies on Antimicrobial and Plant Growth Promoting Efficacy of Fluorescent Pseudomonads

Aims: Excessive use of chemical fungicides cause environmental pollution and its residual effects are deleterious for human and animal consumption. So, application of biological control agents in IDM is an ecofriendly complement to manage the diseases as well as to protect the environment. PGPRs are free living microorganisms which have antimicrobial properties as well as exert beneficial effects to plant growth. Study Design: This present study has been designed to identify potential indigenous fluorescent Pseudomonads strains from different crop ecosystems under Eastern Gangetic plains of West Bengal. Study of Plant growth promoting properties and antimicrobial properties were done under both in-vitro and in vivo condition. Place and Duration of Study: Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, Duration 03years Methodology: Under this experiment 22 bacterial isolates were isolated and purified from different rhizosphere. Isolates were identified based on different biochemical test like catalase, oxidase activity, citrate utilization. The major plant growth promoting properties like P, K and Zn solubilisation efficiency were tested. In-vitro antimicrobial properties were also tested like HCN production, Volatile and non volatile compounds production etc. Based on in-vitro performance, best performing isolate was selected for in-vivo in Lentil against Stemphylium botryosum, a major disease causing fungi of lentil. IDM practice was done in three stages like Seed treatment, Prophylactic spray and Therapeutic spray and three lentil variety WBL 77(Maitree), Pusa Ageti and MN12 were used. Results: Most of the isolates showed positive result in biochemical tests and performed well i.r.o. PGP properties and antimicrobial properties. In field trial UBPF5 gave a promising result. PF5 isolate was identified through 16S rRNA based molecular method and sample showed 99.25% similarity with Pseudomonas gessardii based on nucleotide homology and phylogenetic analysis. In comparison to different combination of treatments cuprous chloride as seed treatment, Pseudomonas sp. as prophylactic spray and for therapeutic purpose Boscalid + Pyroclostrobin were found mostly efficient in respect of disease incidence as well as plant growth and yield. Prophylactic spray with Pseudomonas sp. in combination with biological seed treatment and therapeutic application of fungicide has resulted in 26-38% reduction in disease incidence and 28-32% increment in yield. Conclusion: So, use of PGPR in combination with chemical fungicides is an eco-friendly tool to manage plant diseases in a sustainable manner.

Rhizobia inoculation’s impact on the biomass and moisture content of leguminous Bambara groundnut (Vigna subterranean L. Verdc)

Bambara groundnut (BG) (Vigna subterranean L. verdc) is a highly nutritious underutilized leguminous crop of African origin with high economic importance. Its production rate (300,000 metric tonnes/year) does not meet the current demand (800,000 metric tonnes/year). Despite it’s useful properties, it has remained neglected, with poor market and low yields because research about improving BG has been neglected. rhizobia have proved to be useful in promoting the growth of legumes, yet, there is unavailable information about the role of indigenous BG-symbiont rhizobia inoculant (which are better affordable alternatives to chemical fertilizers) for increasing BG yield and this needs to be explored, hence this study. This experiment studied the role six rhizobial strains in improving the biomass and plant vigour of two selected varieties of BG (TVSU 1248, TVSU 631).These strains were applied as inoculant (at concentrations of > 0.85 × 1010 cfu/ml) on field compared alongside commercial USDA110 strains and Urea (rates of 60 kg/ha and 20 kg/ha) treated plants and analysed for biomass of shoot, root, shaft and seed, and moisture etc. Rhizobia significantly influenced the shoot biomass (≥ 19.26 g), (79.81 ± 1.81 g and 63.15 ± 3.21 g), root biomass (≥ 0.63 g), pod biomass (≥ 155.3 g), seed biomass (≥ 103.96 g), shaff biomass (≥ 52.29 g) and moisture content of the plants, with differences in varietal response. Indigenous BG-symbiotic strains are able to significantly influence plant vigour and biomass, promoting the growth and health of BG. Rhizobia, proved to be useful for enhancing the plant biomass, vigour and growth and should be recommended for improving the production of BG for higher yield and productivity.

Dynamic changes in microbiota and volatile profiles of Marselan wine by single or pairwise inoculated three indigenous non-Saccharomyces yeasts

The object of this study was to compare the effects of three indigenous non-Saccharomyces cerevisiae strains (Hanseniaspora uvarum, Metschnikowia sinensis and Rhodotorula mucilaginosa) and their paired (co-inoculated) fermentation on the microbial communities and volatile profiles during the fermentation of Marselan wine. Results showed that both monoculture and mixed fermentation with non-Saccharomyces strain can complete alcohol fermentation wherein the alcohol content of indigenous yeast treatments were significantly higher than that of control NSD. A total of 44 aroma compounds were identified in all samples, among which the H + R mixed inoculation showed the highest aroma content (28581±1576.61 μg/L). In particular, the contents of ethyl butyrate (V5), ethyl octanoate (V9), and ethyl decanoate (V11) were significantly high, which could enhance the fresh fruit aroma in Marselan wine. Microbial diversity analysis showed that the diversity of fungi between groups was greater than that of bacteria, and H + R (Hanseniaspora and Rhodotorula) had higher microbial abundance (bacteria 79, fungi 78) than the other groups. Spearman correlation analysis revealed that Fructobacillus, Acinetobacter, and other indigenous microorganisms were positively correlated with volatile substances. In summary, the mixed fermentation of Hanseniaspora and Rhodotorula can be considered an effective strategy for improving the aroma quality of Marselan wine. This study provides new insight and useful references for the role and application of native non-Saccharomyces yeast in wine making.

Characterization of Cr(VI)-reducing indigenous bacteria from a long-term tannery waste-contaminated soil

This paper investigated the Cr (VI) detoxification potential of 4 novel bacterial strains isolated from a long-term tannery waste-contaminated soil. Molecular techniques were used to identify the bacterial strains using 16 S rDNA gene sequencing. The Cr (VI) detoxification capacity of the bacteria was determined by 1,5-diphenylcarbazide (DPC) methods. The identified bacterial strains were Bacillus subterraneus MMKT-10, Klebsiella quasivariicola MMKT-15, Acinetobacter seohaensis MMKT-19, and Staphylococcus saprophyticus MMKT-25. All the strains showed maximum tolerance concentration (MTC) of Cr (VI) up to 4000 mg/L. However, in terms of Cr(VI) reduction rate, K. quasivariicola can be considered the most efficient, reducing the two preliminary Cr(VI) concentrations (10 and 20 mg/L) at 15 and 18 h, respectively, while the rest of the strains needed 30 h to reduce the same concentrations from the culture medium. The favorable temperature for Cr(VI) detoxification ranged from 30–40 °C. However, 100 % Cr (VI) reduction was achieved by all the strains at 35 0C. Interestingly, all the bacterial strains reduced a significant amount of Cr (VI) at 50 0C, indicative of their thermotolerant nature. The ideal pH for Cr (VI) reduction was 7 for B. subterraneus MMKT-10 and K. quasivariicola MMKT-15, whereas it was 8 for Acinetobacter seohaensis MMKT-19 and Staphylococcus saprophyticus MMKT-25. The indigenous bacterial strains isolated in this study could be one of the promising candidates for the detoxification of Cr (VI) contaminated sites.

Impact of the use of an indigenous starter on microbial community structuring and aromatic profile of rocamadour protected designation of origin cheese

The use of indigenous strains as starters offers new opportunities that challenge the use of industrial starters, especially to strengthen the link between Protected Designation of Origin (PDO) cheeses and their terroir. This study investigated the effect of two starters, industrial and indigenous, on the microbial ecosystem and volatile organic compounds (VOCs) in Rocamadour PDO cheese. Metabarcoding analysis showed that regardless of the type of starter used, Lactococcus lactis and Geotrichum candidum largely dominated the microbial communities of Rocamadour (>96 %). The analysis of β-diversity based on the Bray-Curtis indices differentiated the starters according to their bacterial communities. VOC analysis showed that the starters were distinguished by three fatty acids characteristic of the goat cheese aroma (p-value <0.05): decanoic, hexanoic, and octanoic acids. Hexanoic acid was not present in cheeses produced with the indigenous starter. This fatty acid was positively correlated with the presence of Paucilactobacillus nenjiangensis, Lactiplantibacillus sp. and Enterobacteriaceae, these microorganisms that were also characteristic of cheeses made with the industrial starter. Octanoic and decanoic acid, on the other hand, were suggested to be correlated with the presence of Leuconostoc mesenteroides.Cheeses produced with the indigenous starter differed in bacterial communities and aromatic signatures.

Effects of light color on growth, nutrient uptake, and harvesting of the indigenous strain of Chlorococcum sp.

Chlorococcum sp. is robust and has dominant growth in aquatic habitats, making it a promising bioresource. This study investigates the batch-wise cultivation and harvesting of Chlorococcum sp. in a standard medium under various lights, followed by biomass harvesting using FeCl3 as a coagulant. The findings highlight the significant impact of light color on growth and nutrient uptake. Specifically, red and blue light promotes growth, followed by white and violet. Following successful cultivation, the coagulation process underwent optimization, determining the optimal dose for harvesting at different cell concentrations (700 mg/L for 3.6 × 106 cells/mL, 600 mg/L for 3.3 × 106 cells/mL, 500 mg/L for 3.2 × 106 cells/mL, and 400 mg/L for 3.0 × 106 cells/mL), each exhibiting high harvesting efficiency. These findings not only advance microalgae cultivation practices but also provide valuable insights into the effective recovery of biomass, potentially expanding the applications of microalgae in various biotechnological fields.

Use of commercial or indigenous yeast impacts the S. cerevisiae transcriptome during wine fermentation.

Understanding microbial functions during wine fermentation, particularly the role of Saccharomyces cerevisiae, is crucial for enhancing wine quality. While commercially available S. cerevisiae strains are commonly used, indigenous strains can offer unique flavors, potentially reflecting vineyard terroir. By leveraging high-throughput DNA sequencing and transcriptomic analysis, we explored the impact of vine age on the grape mycobiome and characterized microbial functions during grape fermentation. Our findings revealed that older vines harbor higher fungal loads, but fungal diversity remains similar across vine ages. Additionally, uninoculated fermentations exhibited diverse fungal dynamics, including the beneficial wine yeasts Metschnikowia and Pichia. Transcriptomic analysis uncovered significant differences in S. cerevisiae gene expression between inoculated and uninoculated fermentations, highlighting the potential of indigenous yeast to enhance wine diversity and inform winemaking practices.

Immune and microbiome modulatory effects of Limosilactobacillus fermentum NCDC 400 in an immunocompromised mouse model

The present study was aimed to assess and validate the safety and functional efficacy of an indigenous probiotic strain Limosilactobacillus fermentum NCDC 400 (hereafter, LFN400) in an immunocompromised murine model. The study included four groups; a normal control (NC) group without immune suppression; an experimental model control (MC) with immune suppression induced via intraperitoneal cyclophosphamide (Cy) administration; and two MC groups orally administered with either low dose (LD) or high dose (HD) of LFN400 at dose 108 and 1010 CFU/mouse/day, respectively, for 15-days. Both control groups received normal saline as placebo control. LFN400 improved specific experimental characteristics including hematological and serum biochemical markers. Compared to MC group, LFN400-fed groups showed markedly (P < 0.05) decreased arrays of detrimental caecal enzymes. We did not observe instances of bacterial translocation of LFN400 from gut to bloodstream or extra-intestinal organs. LFN400 intake significantly (P < 0.05) enhanced spleen cell differentiation, immune and oxidative stress markers, and restored Cy-induced histopathological changes in multiple tissues, including the spleen. There was no genotoxic effect of LFN400 on bone marrow cells. Although not statistically significant, LFN400 feeding moderately increased gut microbiome diversity, supporting the growth of beneficial saccharolytic microorganisms and reducing the presence of pathobionts. The findings demonstrate that the probiotic strain LFN400 possesses in vivo safety and immunomodulatory potency and thus should be considered a potential candidate for future human clinical studies.

Evaluation of probiotic efficacy of indigenous yeast strain, Saccharomyces cerevisiae Y-89 isolated from a traditional fermented beverage of West Bengal, India having protective effect against DSS-induced colitis in experimental mice.

Increasing awareness regarding health promotion and disease prevention has driven inclusion of fermented foods and beverages in the daily diet. These are the enormous sources of beneficial microbes, probiotics. This study aims to isolate yeast strains having probiotic potential and effectivity against colitis. Initially, ninety-two yeast strains were isolated from Haria, an ethnic fermented beverage of West Bengal, India. Primary screening was done by their acid (pH 4) and bile salt (0.3%) tolerance ability. Four potent isolates were selected and found effective against Entamoeba histolytica, as this human pathogen is responsible to cause colitis. They were identified as Saccharomyces cerevisiae. They showed luxurious growth even at 37 oC, tolerance up to 5% of NaCl, resistance to gastric juice and high bile salt (2.0%) and oro-gastrointestinal transit tolerance. They exhibited good auto-aggregation and co-aggregation ability and strong hydrophobicity. Finally, heat map and principal component analysis revealed that strain Y-89 was the best candidate. It was further characterised and found to have significant protective effects against DSS-induced colitis in experimental mice model. It includes improvement in colon length, body weight and organ indices; reduction in disease activity index; reduction in cholesterol, LDL, SGPT, SGOT, urea and creatinine levels; improvement in HDL, ALP, total protein and albumin levels; decrease in coliform count and restoration of tissue damage. This study demonstrates that the S. cerevisiae strain Y-89 possesses remarkable probiotic traits and can be used as a potential bio-therapeutic candidate for the prevention of colitis.

Identification of Indigenous Bacterial Strains from Thai Agricultural Fields for Potential Bioremediation of Carbofuran

This study explored the bioremediation potential of indigenous soil bacteria for carbofuran-contaminated agricultural areas. Twenty soil samples from regions with a history of pesticide use in Pathum Thani and Nakhon Pathom provinces, Thailand, were collected. Five bacterial strains capable of degrading carbofuran were isolated and subjected to cell morphology and biochemical analyses. Phylogenetic analysis of the 16S rRNA gene sequences identified these strains as related to Pseudomonas and Stenotrophomonas species. High-Performance Liquid Chromatography (HPLC) analysis confirmed the complete degradation of carbofuran within 3 days, reducing its concentration from 0.05 mg/mL to below detectable limits. These bacteria could use carbofuran as their sole carbon source, demonstrating their potential for bioremediation of contaminated soils. Given their resilience and ability to thrive in natural environmental conditions, these indigenous strains are well-suited for in-situ degradation of pollutants. The findings indicate that these isolated soil bacteria present a promising method for reducing the environmental risks associated with carbofuran contamination.

Metabolite profiling and molecular characterization of NBAIR BSWG1: A potential strain of Bacillus subtilis against Fusarium oxysporium f. sp. udum

To address the fungal wilt of pigeon pea caused by Fusarium oxysporium f. sp. udum, farmers currently rely on chemical fungicides, despite their harmful effects. However, there is a growing need for safer alternatives like green pesticides. Bacterial biocontrol agents and their derivatives serve as potential green pesticides in the management of plant pathogens. In the present study, we aimed to identify indigenous Bacillus subtilis strains effective against F. oxysporium f. sp. udum. We used PCR and MALDI-TOF analysis to identify the active components responsible for the efficiency of efficient strain. Biochemical studies of cell-free extracts extracted from B. subtilis strains demonstrated the highest biosurfactant activity in NBAIR BSWG1, with an oil displacement of 2 cm and an emulsification index of 60 %. Molecular characterization confirmed the presence of surfactin, fengycin, and iturin coding genes in the B. subtilis strains, among them, NBAIR BSWG1 showed the highest number of lipopeptide-producing genes. Meanwhile, NBAIR BSWG1 showed inhibition of 79.84 % against F. oxysporium f. sp. udum using cell-free extract. Further metabolite profiling of NBAIR BSWG1 using MALDI-TOF analysis further confirmed surfactin, fengycin, and iturin in the purified cell-free extract of NBAIR BSWG1. Two peaks with m/z of 923.77 and 1149.92 were identified as novel lipopeptide compounds which need further characterization. The present study identified NBAIR BSWG1 as an efficient bacterial strain for the inhibition of F. oxysporium f. sp. udum and its antifungal properties are mainly due to the production of cyclic lipopeptides.

Yeast Diversity in Wine Grapes from Japanese Vineyards and Enological Traits of Indigenous Saccharomyces cerevisiae Strains.

Japan has numerous vineyards with distinct geographical and climatic conditions. To the best of our knowledge, there is no comprehensive analysis of the diversity of yeasts associated with wine grapes from Japan. This study aimed to determine yeast diversity in wine grapes from four wine-producing regions in Japan and to evaluate the physicochemical characteristics of wines produced with indigenous Saccharomyces cerevisiae strains isolated from two regions. A total of 2648 strains were isolated from nine wine grape samples. MALDI-TOF MS and 26S rDNA sequence analyses revealed that the strains belonged to 21 non-Saccharomyces yeasts and 1 Saccharomyces yeast (S. cerevisiae). Non-Saccharomyces yeasts were found in high quantities and were highly distributed among the wine grape samples. Differences in the distribution of the identified yeast species were noted among the different wine grape varieties and regions. Indigenous S. cerevisiae strains of different genotypes from different regions exhibit distinct physiological traits. Our findings are expected to enhance our understanding of the local yeasts associated with Japanese vineyards and contribute to obtaining cultures that can provide region-specific organoleptic characteristics to local wines produced in Japan.

Novel Indigenous Strains and Communities with Copper Bioleaching Potential from the Amolanas Mine, Chile

Bioleaching, a process catalyzed by acidophilic microorganisms, offers a sustainable approach to metal extraction from sulfide minerals. Chalcopyrite, the world’s most abundant copper sulfide, presents challenges due to surface passivation limiting its bioleaching efficiency. Also, indigenous species and microbial communities may present high copper extraction rates and offer new possibilities for application in bioleaching processes. This study examines the bioleaching potential of microbial isolates and communities obtained from Amolanas Mine in Chile. Samples were collected, cultivated, and identified by Sanger sequencing. The bioleaching potential and biofilm formation of isolates and enrichments were evaluated on pyrite and chalcopyrite. The results show the isolation of nine Leptospirillum and two Acidithiobacillus strains. The bioleaching experiments demonstrated good copper bioleaching potentials of the Leptospirillum I2CS27 strain and EICA consortium (composed mainly of Leptospirillum ferriphilum, Acidiphilium sp., and Sulfobacillus thermosulfidooxidans), with 11% and 25% copper recovery rates, respectively. Microbial attachment to the surface mineral was not mandatory for increasing the bioleaching rates. Our findings underscore the importance of indigenous microbial communities in enhancing copper bioleaching efficiency.