Bacillus Safensis Research Articles

Response of Black Gram to Seed Biopriming with Facultative Halophilic Bacteria under Salinity

Under high salinity conditions, plant growth promoting halophilic bacteria (PGPHB) can thrive and greatly encourage plant growth. The use of PGPHB is minimal and less discussed in sustainable agriculture and abiotic stress control. The focus of the current investigation is to improve the growth of black gram by inoculating with of halophilic bacteria under salinity stress. Four PGPHB bacteria, viz., Bacillus safensis strain Lewis_Bac_3 (HB-5), Pseudomonas stutzeri strain MN1 (HB-13), Staphylococcus xylosus strain C5 (HB-18) and Pseudomonas sp. (GP-21: reference strain) were inoculated to black gram seeds to evaluate their plant growth promoting ability at 4 dS m-1 and pH >8.5. Increase in root length, plant height, and number of branches have been reported in consortium treatment (T8), indicating that salinity does not affected black gram photosynthesis and nutrient absorption in consortium treatment. Corroborating evidence revealed higher nodulation and total nitrogen and phosphorous content in the same treatment, in comparison with control. Due to salinity stress, decreased blooming was reported in control, conversely, consortium treatment showed 29.3 flowers/plant. A positive correlation with yield was demonstrated by number of pods and seeds per pod of black gram. In addition, there is a strong association between pods per plant and the amount of flowers per plant, nutrient content, and length of root. The decrease in control plot yield was due to shoot and root development resulting from insufficient nutrients availability. In this study we also found positive correlation between% P in plant and yield. Hence, we conclude that PGPH bacteria helps in the reduction of salt stress and significantly increase black gram growth and yield under mild salinity stress.

Bacillus spp. metabolites are effective in eradicating Aedes aegypti (Diptera: Culicidae) larvae with low toxicity to non-target species

The growing spread of dengue, chikungunya and Zika viruses demand the development of new and environmentally safe control methods for their vector, the mosquito Aedes aegypti. This study aims to find novel larvicidal agents from mutualistic (endophytic and rhizospheric) or edaphic bacteria that have no action against non-target organisms. Eleven out of the 254 bacterial strains tested were able to kill Ae. aegypti larvae. Larvicidal activity did not depend on presence of cells, since culture supernatants or crude lipopeptide extracts (CLEs) killed the larvae. Bacillus safensis BacI67 and Bacillus paranthracis C21 supernatants were the best performing supernatants, displaying the lowest lethal concentrations (LC50 = 31.11 µL/mL and 45.84 µL/mL, respectively). Bacillus velezensis B64a and Bacillus velezensis B15 produced the best performing CLEs (LC50 = 0.11 mg/mL and 0.12 mg/mL, respectively). Mass spectrometry analysis of CLEs detected a mixture of surfactins, iturins, and fengycins. The samples tested were weakly- or non-toxic to mammalian cells (RAW 264.7 macrophages and VERO cells) and non-target organisms (Caenorhabditis elegans, Galleria mellonella, Scenedesmus obliquus, and Tetrahymena pyriformis) – especially B. velezensis B15 CLE. The biosynthetic gene clusters related to secondary metabolism identified by whole genome sequencing of the four best performing bacteria strains revealed clusters for bacteriocin, beta-lactone, lanthipeptide, non-ribosomal peptide synthetases, polyketide synthases (PKS), siderophores, T3PKS, type 1 PKS-like, terpenes, thiopeptides, and trans-AT-PKS. Purification of lipopeptides may clarify the mechanisms by which these extracts kill Ae. aegypti larvae.

Cellulolytic Bacillus species isolated from the gut of the desert locust Schistocerca gregaria

The ability of many insects to thrive on wood, foliage, and detritus has stimulated an interest on the potential use of gut microbial flora of such species as a bioresource for industrial conversion of cheap cellulosic material into bioproducts. In this study, the capacity of intestinal flora from the gut of Schistocerca gregaria to degrade cellulose model compound was investigated. Two Bacillus species were isolated, their cellulose degradation capacity determined by zone clearance assay on agar plates and later identified by 16S rDNA gene sequencing. The two isolates had relatively high cellulolytic activity with ICA (Index Cellulolytic Activities) values of 1.146 ± 0.109 and 0.8442 ± 0.09203, and were identified as Bacillus safensis strain MED1 and Bacillus safensis strain CACO respectively. The 16S rDNA sequences were deposited to GenBank under accession numbers JQ 837242.1 and JQ 837243.1.

Antibacterial and Anticancer Activity and Untargeted Secondary Metabolite Profiling of Crude Bacterial Endophyte Extracts from Crinum macowanii Baker Leaves.

This study isolated and identified endophytic bacteria from the leaves of Crinum macowanii and investigated the potential of the bacterial endophyte extracts as antibacterial and anticancer agents and their subsequent secondary metabolites. Ethyl acetate extracts from the endophytes and the leaves (methanol: dichloromethane (1 : 1)) were used for antibacterial activity against selected pathogenic bacterial strains by using the broth microdilution method. The anticancer activity against the U87MG glioblastoma and A549 lung carcinoma cells was determined by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Bacterial endophytes that were successfully isolated from C. macowanii leaves include Raoultella ornithinolytica, Acinetobacter guillouiae, Pseudomonas sp., Pseudomonas palleroniana, Pseudomonas putida, Bacillus safensis, Enterobacter asburiae, Pseudomonas cichorii, and Arthrobacter pascens. Pseudomonas cichorii exhibited broad antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria while Arthrobacter pascens displayed the least MIC of 0.0625 mg/mL. Bacillus safensis crude extracts were the only sample that showed notable cell reduction of 50% against A549 lung carcinoma cells at a concentration of 100 μg/mL. Metabolite profiling of Bacillus safensis, Pseudomonas cichorii, and Arthrobacter pascens crude extracts revealed the presence of known antibacterial and/or anticancer agents such as lycorine (1), angustine (2), crinamidine (3), vasicinol (4), and powelline. It can be concluded that the crude bacterial endophyte extracts obtained from C. macowanii leaves can biosynthesize bioactive compounds and can be bioprospected for medical application into antibacterial and anticancer agents.

Investigation of the bacterial modified waste PET aggregate VIA Bacillus safensis to enhance the strength properties of mortars

Polyethylene terephthalates (PET), which are highly resistant to degradation under natural environmental conditions due to their inert, hydrophobic and high molecular weights, are collected in landfills or dispersed as waste. Considering the increasing use of PET, the interest in multidisciplinary studies aimed to obtaining high value added products from PET wastes has increased. In this study, the potential of using waste plastics made of Polyethylene terephthalate (PET) treated with bacteria as an aggregate in the production of mortar was investigated. First, the bacterial strains, which secreted esterase or cutinase, were screened for their ability to attach to hydrophobic surfaces and biofilm formation. TH401, which showed potential for the modification of the PET aggregates, was identified as Bacillus safensis. To enhance the compatibility of the PET, the waste PET aggregates were treated with submerged fermentation via B. safensis TH401. The FTIR analyses conducted after the treatment showed that the chemical structure of the PET had been modified. Mortar samples were prepared by using the modified PET aggregates. The compressive and flexural tensile strength values of the samples were measured on days 7, 28 and 56. The compressive strength values of the bacteria modified samples were 4.87%, 7.51% and 13.13% higher than the non-bacterial samples at 22 °C, 30 °C and 50 °C, respectively. The increase in curing temperatures had a positive effect on compressive and flexural tensile strength values. The highest strength values were obtained in the samples cured at 50 °C. In the EDX spot of the mixtures, major peaks of C, O, Ca were detected indicating the presence of CaCO3 and bacteria. Stratification on the PET surface as a result of bacterial modification was clearly observed in the SEM images. The test results showed that bacterial modification contributed to the increase in the strength of the waste PET aggregate concrete. It can be said that mortars produced with bacteria modified PET aggregates can be used as an economical and environmentally friendly material alternative in the construction industry.

Exopolysaccharides and indole-3-acetic acid producing Bacillus safensis strain FN13 potential candidate for phytostabilization of heavy metals

Microbial population of soils irrigated with industrial wastewater may contain certain exopolysaccharides (EPS) and indole-3-acetic acid (IAA) producing bacterial strains having the ability to tolerate heavy metals along with plant growth-promoting (PGP) traits. As cadmium is one of the most toxic heavy metals for soils, plants, animals, and human beings, the present study was planned to isolate and characterize EPS- and IAA-producing, Cd-tolerant bacterial strains having tolerance against heavy metals along with plant growth-promoting traits. A total of 30 rhizobacterial strains (FN1-FN30) were isolated from rhizosphere soil collected from fields around industrial areas and roadsides irrigated with industrial wastewater. Out of these, eight isolates with the combined ability of IAA production and EPS production were characterized for PGP traits. On the basis of multifarious PGP traits and the results of root colonization assay, three most efficient EPS- and IAA-producing, Cd-tolerant plant growth-promoting strains, i.e., FN13, FN14, and FN16, were selected for multiple metal (Cd, Pb, Ni, and Cu) tolerance test along with quantification of growth, and IAA and EPS production abilities under Cd stress. Increasing levels of Cd stress negatively affected the tested characteristics of these strains, but FN13 showed more stability in growth, IAA production (18.24 μg mL-1), and EPS production (148.99 μg mL-1) compared to other strains under Cd stress. The morphological and biochemical analysis confirmed FN13 as Gram-positive, rod-shaped bacteria with smooth colonies of yellow appearance. The strain FN13 has strong root colonization (3.36 × 106 CFU g-1) ability for mustard seedlings and can solubilize Zn and phosphate along with the production of HCN, ammonia, and siderophores. The 16S rRNA sequencing confirmed it as the Bacillus safensis strain FN13. It can be explored as potential phytostabilizing biofertilizer for heavy metal-contaminated soils.

In vitro microcosm of co-cultured bacteria for the removal of hexavalent Cr and tannic acid: A mechanistic approach to study the impact of operational parameters

Industrial wastes, for instance, tannery wastes are rich soups of resistant and bioremediation-potent bacteria. In the present work, Chromium (Cr) and tannic acid (TA) resistance bacterial strains were isolated from tannery effluent and identified as Bacillus subtilis (MCC 3275) and Bacillus safensis (MCC 3283) based on its 16S Ribosomal RNA homology. Hexavalent Cr is highly toxic and mutagenic due to its high mobility and reactivity. Whereas, TA is known to inhibit enzyme activity, substrate deprivation, and interaction with membranes and matrix-metal ions. The developed In vitro co-cultured microcosm of B. subtilis and B. safensis was able to remove Cr(VI) up to 95% and TA up to 23%. The bacteria cultures separately were able to degrade Cr(VI) to 88% by B. subtilis and 91% by B. safensis and TA up to 27%. Plackett Burman design (PBD) followed by Response surface methodology (RSM) was applied for the optimization of physio-chemical parameters. The optimized conditions for co-culture development were recorded as K2HPO4 = 0.2 g/L, MgSO4 = 0.2 g/L, NH4Cl = 0.5 g/L, glucose – 0.2 g/L, TA – 5%, Cr = 200 ppm, incubation period of 96 h, agitation speed of 110 rpm, pH = 5.0, temperature= 30 °C and inoculum size = 3%. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) revealed the thorough mechanism of cellular uptake followed by degradation of Cr(VI) and TA. The efficiency of co-culture for other heavy metals was observed as follows: Zn 65%, Pb 63%, Cd 65%, and Ni 65%. Bioremediation using bacteria is an economical and environmentally better alternative to conventional remediation methods. The isolated bacteria are useful in the effluent treatment of tannery or related industries and in metal recovery in mining processes.

Culturable bacterial endophytes isolated from citrus leaves enhance seedling growth of Solanum melongena L.

Endophytes have a symbiotic relationship with plants and play an important role in supporting the plant growth. The objective of this study was to examine the effect of endophytic bacteria isolated from citrus leaves on promoting seedling growth and influencing some biochemical attributes in brinjal (Solanum melongena L.). Isolated bacteria were characterized based on molecular tool 16S rRNA. The bacterial isolates were identified as Enterococcus faecalis, Brevibacillus borstelensis, Staphylococcus haemolyticus, Bacillus safensis, B. megaterium, B. cereus, Pseudomonas sp., P. aeruginosa, Enterobacter hermachei and Proteus mirabilis based on 16S rRNA sequence homology and phylogenetic analysis. The leaves of brinjal seedlings were inoculated with these bacterial endophytes by injection method under greenhouse conditions. About one month after inoculation, the plants were analysed for their physical (shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight,), bio-physical (chlorophyll a and b contents, and relative leaf water content), and biochemical (total phenolic, flavonoids and carotenoids contents) parameters. In the present study, Bacillus safensis and Pseudomonas sp. significantly increased the shoot length, shoot fresh and dry weights, relative leaf water content, leaf chlorophyll b content, phenolics and flavonoids in brinjal plants after the application of the bacterial inoculum. However, carotenoids content remained unaffected by the bacterial inoculum. Thus, some bacterial endophytes possess prospective potential in improving plant growth and could be used as inoculants to establish a sustainable crop production system.

Role of biocontrol agents on chlorophyll content in wilt affected lentil crop

In the present study biocontrol agents Bacillus safensis and Bacillus licheniformis has been isolated from wilt affected lentil crop of agro-climatic zone of eastern UP like Faizabad, Mau, Varanasi, Gazipur.Lentil seed treatment has been given by these isolated strains as bioagents against wilt pathogen in pot experiment in lentil crop Rabi-season 2019-2020.Result of conducted pot experiment showed the maximum chlorophyll content was found in T3 (Bacillus safensis +Bacillus licheniformis +Fusarium oxyporum f.sp.lentis+Lentil Rasistant variety IPL-316 + Susceptible variety K-75.) followed by treatments T2 (Bacillus licheniformis +Resistant Variety IPL-316+Susceptible variety K-75 ) and T1 (Bacillus safensis +Lentil Resistant variety IPL-316 + Susceptible Variety K-75) as compare to negative control T5 (Lentil Resistant variety IPL-316 + Susceptible Variety K-75+No bacterium inoculum) and pathogen T4(Fusarium oxysporum f.spp.lentis + Resistant variety IPL-316 + Susceptible Variety K-75. The aim of this paper is to study the bio-agent’s factor affecting the chlorophyll content and provide protection against pathogen in lentil plant. After that chlorophyll estimation test was performed on treated lentil crop on 30, 60 and 90 days. We observed chlorophyll content in treated crops and maximum chlorophyll content was found at 30 and 60 days which minimize at 90 days.

Bioactive compound isolated from marine Bacillus safensis MB8 and their cytotoxicity potential

Bioactive compound isolated from marine Bacillus safensis MB8 and their cytotoxicity potential

Autochthonous halotolerant plant growth-promoting rhizobacteria promote bacoside A yield of Bacopa monnieri (L.) Nash and phytoextraction of salt-affected soil

Phytoremediation is a promising approach for reclamation of salt-affected soil. Phytoextraction is the most commonly used process, which exploits plants to absorb, immobilize, and accumulate salt in their shoots. In this study, halotolerant plant growth-promoting rhizobacteria (PGPR) were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow, Uttar Pradesh (India) and were tested for their efficacies of salt-tolerance and plant growth-promoting (PGP) abilities. Based on 16S rRNA sequences, the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida (KM233646), Acinetobacter calcoaceticus (KM233647), Bacillus flexus (KM233648), and Bacillus safensis (KM233652). Application of these isolates as bio-inoculants significantly (P < 0.05) increased the growth and bacoside A yield of a medicinal plant, Bacopa monnieri (L.) Nash, grown on natural salt-affected soil. The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na+:K+ ratio of bio-inoculant-treated plants. When compared to un-inoculated control plants, the soil physico-chemical properties of bio-inoculant-treated plants were improved. The shoot and root biomass (fresh and dry weights), soil enzymes, and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ ratio. Consequently, the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.

Synergic Involvements of Microorganisms in the Biomedical Increase of Polyphenols and Flavonoids during the Fermentation of Ginger Juice

Steered fermentation by microorganisms gives great added value in the nutritional quality of local food. Ginger rhizome naturally contains a myriad of bioactive compounds including polyphenol and flavonoids. The aim of this work was to ferment the ginger juice, to evaluate the biochemical parameters of ginger wine, and to understand the involvement of microorganisms in the bioincrease of polyphenol compounds. Titratable acidity and pH values were determined and showed that pH is around 1.6 at the end of the fermentation when the acidity is around 6.431 g/L. Using colorimetric assay, the total polyphenolic and flavonoid compounds were evaluated throughout the fermentation. The variation of the polyphenol and flavonoid concentrations of the unsweetened sample was around 10.18 to 14.64 mg Eq AG/g and 1.394 to 2.224 mg Eq Cat/g Ms, but those from the sweet sample were around 10.82 to 18.34 mg Eq AG/g Ms and 1.311 to 2.290 mg Eq Cat/g. Using one-step PCR, multiplex techniques with specific primers, with yeast-like phenotype 27.27% (6), have been assigned among 22 isolates to Saccharomyces cerevisiae. By using PCR multiplex techniques, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, and Saccharomyces cerevisiae have been identified. Together with Saccharomyces cerevisiae, we showed that Bacillus sp. are able to secrete enzymatic landscape with some activities up to 50% including cellulase, amylase, pectinase, and protease.

Biodegradation of the fungicide Pyraclostrobin by bacteria from orange cultivation plots

The pesticides belonging the strobilurin group are among the most common contaminants in the environment. In this work, biodegradation studies of the strobilurin fungicide Pyraclostrobin by bacteria from orange cultivation plots were performed aiming to contribute with the development of a bioremediation method. Experiments were performed in triplicate with validated methods, and optimization was performed by Central Composite Design and Response Surface Methodology. The strains were evaluated in liquid nutrient medium containing 100 mg L−1 of Pyraclostrobin, and decreased concentrations of 61.5 to 100.5 mg L−1 were determined after 5 days at 37 °C and 130 rpm, showing the importance of strain selection. When the five most efficient strains (Bacillus sp. CSA-13, Paenibacillus alvei CBMAI2221, Bacillus sp. CBMAI2222, Bacillus safensis CBMAI2220 and Bacillus aryabhattai CBMAI2223) were used in consortia, synergistic and antagonistic effects were observed accordingly to the employed combination of bacteria, resulting in 64.2 ± 3.9 to 95.4 ± 4.9 mg L−1 residual Pyraclostrobin. In addition, the formation of 1-(4-chlorophenyl)-1H-pyrazol-3-ol was quantified (0.59–0.01 mg L−1), and a new biodegradation pathway was proposed with 15 identified metabolites. Experiments were also performed in soil under controlled conditions (30 °C, 0–28 days, 100 mg kg−1 pesticide), and the native microbiome reduced the pesticide concentration to 70.4 ± 2.3 mg L−1, whereas the inoculation of an efficient bacterial consortium promoted clearly better results, 57.2 ± 3.9 mg L−1 residual Pyraclostrobin. This suggests that the introduction of these strains in soil in a bioaugmentation process increases decontamination. However, the native microbiome is important for a more efficient bioremediation.

Study of fermented feed by mixed strains and their effects on the survival, growth, digestive enzyme activity and intestinal flora of Penaeus vannamei

In this study, the mixed strains, including Lactobacillus plantarum (STBL1), Saccharomyces cerevisiae (STBS1), and Bacillus safensis (SQVG18) were applied to the solid-state fermentation of commercial feed for Penaeus vannamei. Firstly, the optimum combination of strain inoculum, optimum fermentation conditions, and nutritional quality of the fermented feeds were investigated. It was noted that the acid-soluble protein and the content of amino acids (lysine, methionine, etc.) were remarkably improved in the feeds by solid-state fermentation with the optimum combination of STBL1: STBS1: SQVG18 = 1: 3: 3. Secondly, a six-week feeding experiment was performed using one control diet without probiotics (D0: 0 CFU g−1) and three fermented diets containing different concentrations of the optimum mixed-strain combination (D1: 107 CFU g−1; D2: 108 CFU g−1; D3: 109 CFU g−1). Shrimps fed D2, and D3 groups exhibited significantly better growth performance and activities of antioxidant enzymes and digestive enzymes than shrimp of other groups (P < .05). The fermented feeds also affected the intestinal microflora of P. vannamei at the end of the feeding trial. The diversity indices, composition, and functional prediction of microbial communities showed that shrimp fed D1 and D2 groups had a better microecological environment in intestines. Overall, the fermented diet with mixed strains of 108 CFU g−1 may be conducive to the growth and health of P. vannamei by improving growth, antioxidant capacity, digestion, and gut microflora.

Screening of Siderophore-Producing PGPRs Isolated from Groundnut (Arachis hypogaea L.) Rhizosphere and Their Influence on Iron Release in Soil

ABSTRACT Iron is indispensable for the growth and metabolism of all living organisms but its availability in soil is limited due to very low solubility of dominant ferric iron (Fe3+). Plant growth-promoting rhizobacteria (PGPRs) have the ability to synthesize low molecular weight siderophores having high affinity for iron. Considering the siderophore-producing ability of PGPRs, a study was designed to isolate potential siderophore-producing bacteria from the rhizosphere of groundnut grown in the Potohar region. A total of 120 (MGS-1 to MGS-120) different bacterial isolates were obtained and screened for siderophore production. Under the quantitative estimation of siderophores, the maximum (73%) siderophore production was observed in MGS-14 followed by MGS-11 (69%) and MGS-91 (68%). Furthermore, these isolates were used for the incubation study which was conducted to evaluate the effect of SPB isolates on iron release in the soil. The soil was incubated at 28°C for 96 days and field capacity was maintained with distilled water from time to time. The results of the study revealed that the three SPB isolates (MGS-11, MGS-14, and MGS-91) which produced maximum siderophore units (>60% SU) showed an increase in iron release and 82%, 71%, and 69% over control on 32nd day of incubation, respectively. Moreover, the efficient bacterial isolates were characterized through 16S rRNA gene sequence analysis. The identified bacterial isolates were Bacillus subtilis, Bacillus halotolerans, and Bacillus safensis.

Bacteria from industrial waste: potential producers of polyhydroxyalkanoates (PHAs) in Manizales, Colombia.

Polymers are currently used in the industry as raw material, yet they are rapidly eliminated and largely contaminate the environment. To address this issue, there is a special interest in biodegradable polymers, namely, polyhydroxyalkanoates (PHAs), produced by microorganisms. This study identifies PHA-producing bacteria from two industrial wastewaters of Manizales, Colombia. The samples were cultured in mineral salt medium with glucose as the carbon source in the presence of Nile red stain. The fluorescent colonies were independently transferred to another medium and assessed through fluorescence microscopy with Nile blue stain. The fluorescent strains under Nile blue staining were purified in Nutrient Agar, and their morphological and microbiological characteristics were determined. The bacteria positive for red-orange fluorescence were purified in Nutrient Agar medium, and molecular analyses were performed by PCR amplification of a 650-bp fragment of the 16S ribosomal DNA gene. The bacteria were also assessed in terms of PHA production. We confirmed the identity of 12 out of 14 PHA-positive strains, which belonged to the following genera: Bacillus, Lactococcus, Citrobacter, Enterobacter, and Acinetobacter. Five of the isolates (Enterobacter cloacae, Enterobacter sp., Enterobacter ludwigii, Bacillus thuringiensis, and Bacillus safensis) are promising strains for PHA production, with production values ranging from 0.360 to 0.9960g/L. Bacteria that produce more than 0.3g/L are considered useful for the industrial manufacture of bioplastic. We recommend performing large-scale studies on these strains to assess their use for the industrial production of biopolymers, allowing to generate high-impact bioconversion processes of industrial interest.

Suppression of Rice Blast by Bacterial Strains Isolated from Cultivated Soda Saline-Sodic Soils.

Rice blast caused by Magnaporthe oryzae is one of the most serious rice diseases worldwide. Biological control is gaining popularity as a promising method for the control of this disease; however, more effective microbial strains with strong adaptability in rice fields need to be identified. Here, we report for the first time the successful identification of biocontrol bacterial strains from frozen soils of the soda saline-sodic land. We isolated 82 bacterial strains from rice fields in the western Songnen Plain of China, one of the three major soda saline soils in the world. Five of the isolated strains exhibited strong inhibition to M. oryzae growth. The potential strains were identified as Bacillus safensis JLS5, Pseudomonas koreensis JLS8, Pseudomonas saponiphila JLS10, Stenotrophomonas rhizophila JLS11 and Bacillus tequilensis JLS12, respectively, by 16s RNA gene sequence analysis. The antagonistic assay and the artificial inoculation tests showed that JLS5 and JLS12 could effectively inhibit conidial germination and pathogenicity of the rice blast fungus, both preventively and curatively. The suppression of pathogenicity was further confirmed by greenhouse experiments, showing the effectiveness of JLS5 and JLS12 as a potential biological control agents of M. oryzae. The potential application of these cold-tolerant strains for rice blast control in cold regions is discussed. Our data suggest that soda saline-sodic soils are a rich source for biocontrol strain isolation.

Endophytic bacilli from medicinal-aromatic perennial Holy basil (Ocimum tenuiflorum L.) modulate plant growth promotion and induced systemic resistance against Rhizoctonia solani in rice (Oryza sativa L.)

Among the twenty-one bacterial endophytes isolated from Holy basil (Ocimum tenuiflorum), eight were potentially inhibiting the growth of five plant pathogens. Percent suppression of Rhizoctonia solani, Sclerotium rolfsii, Alternaria alternata, Microphomina phaseolina, and Bipolaris sorokiniana radial growth was significantly higher by isolates BTL-4 (70.64%), BTL-1 (80.63%), BTL-1 (57.50%), BTL-5 (81.28%), and GTS-15 (73.81%), respectively. Based on 16S rRNA gene sequencing, these isolates were putatively identified as Bacillus altitudinis (BTL-1 and GTS-16), Bacillus tequilensis (BTL-4), Bacillus safensis (BTL-5), Bacillus haynesii (GTR-8), Bacillus paralicheniformis (GTR-11), Bacillus pacificus (GTR-12), and Bacillus siamensis (GTS-15). Selected endophytes were tested against R. solani in vivo and found to reduce sheath blight disease incidence to a varying extent. Rice plants challenged with R. solani and inoculated with Bacillus altitudinis GTS-16 exhibited the least value of percent infected tillers, recorded maximum induction of defense-related enzymes (phenyl ammonia lyase, peroxidase, and polyphenol oxidase), and enhanced dry matter accumulation. Confocal Scanning Laser Microscope imaging using LIVE/DEAD™BacLight™ bacterial viability staining has indicated trans-genera colonization of O. tenuiflorum endophytes in rice. Exploring the potential niches like the endosphere could open the vast arena of opportunity for developing newer strains of biocontrol agents.

Characterization of Bacterial Flora from Afşin–Elbistan Lignite Mine for Potential Microbial Biotech Applications

The energy demand is enhancing day by day all over the world with the increasing of huge population. Lignite, a fossil fuel with low energy efficiency, is used in many different fields. However, lignite is primarily an energy source and its use without treatment causes environmental pollution as well as low energy efficiency. Advantages are known for the use of microorganisms in lignite processing technologies, and research is underway to improve this process. In this research designed to meet this need, isolation and characterization of bacteria with potential for use in biotechnological applications resistant to extreme conditions were performed from lignite mine. Turkey’s largest lignite mine bacterial flora have been identified for the first time in this study. In addition to lignite processing technologies, a bacterial strain collection has been created to be used in other biotechnological studies. This collection of bacteria includes Methylorubrum zatmanii, Streptomyces argenteolus, Streptomyces galilaeus, Pseudomonas mandelii, Paenarthrobacter aurescens, Paeniglutamicibacter sulfureus, Arthrobacter humicola, Bacillus pumilus, Bacillus subtilis, Bacillus safensis, Kocuria polaris, Arthrobacter sp., Rhodococcus sp. This specific bacteria collection is open to sharing with other researchers who want to do field applications.

Mining Saline Soils to Manifest Plant Stress-Alleviating Halophilic Bacteria.

The connection between soil and microbes plays a critical role in soil health and quality and can be elastic with the application of soil amendments and/or crop rotations. Inappropriate management of soil and application of impermissible levels of fertilizers ruptures the overriding connection between the soil and microbes. This is currently evidenced in the degraded soils (i.e., saline soils of India) which are caused by modern agricultural practices. Reclamation of saline soils with a saturated package of practices and conventional breeding methods requires biological intervention. Shortfall of nutrients is one of the chief constraints for plant growth in salt-affected soils. In the present investigation, we have observed an arsenal of fifty halophilic bacteria carrying an absolute requirement of 3% NaCl for solubilizing the insoluble minerals (ZnCO3, ZnO, Mica and tri-calcium phosphate) under in vitro conditions; however, increasing the amount of NaCl over and above resulted in loss of solubilization capacity. Of the isolates solubilizing zinc carbonate and zinc oxide at 3% NaCl concentration, there were 29 isolates; at 10% concentration, 10 isolates were positive for the presence of zinc carbonate. At 3% NaCl concentration, HB-5 showed 23.16mm zinc carbonate solubilization, HB-20 showed 13.3mm Zinc oxide solubilization, and HB-7 showed 13.4mm tri-calcium phosphate solubilization. Mica solubilization was peaked at 6% NaCl and maximum solubilization was observed in HB-27 (18.03mm). When compared to the zinc carbonate solubilization, zinc oxide solubilization was slow to reach desired levels. Solubilization lasted for up to 9days and ceased thereafter in all the tests. Eight elite isolates were identified as Bacillus albus, Bacillus safensis, Pseudomonas stutzeri (2), Lysinibacillus sphaericus, Staphylococcus xylosus, and Bacillus cereus (2) based on 16S rRNA analysis.