Bacillus Firmus Research Articles

Biodiversity and antifouling activity of microbes associated with gorgonian corals Leptogorgia rigida and Menella kanisa from the South China Sea

Recently, coral-associated microorganisms have attracted widespread attention, and most of these studies have focused on stony and soft corals. However, our knowledge of the diversity and bioactivity of microorganisms in gorgonian corals is still limited. In this study, the biodiversity of microbes in two gorgonian corals (Leptogorgia rigida and Menella kanisa) from the South China Sea was investigated by combining traditional culture method with molecular biology technique (bacterial 16S or fungal internal transcribed spacer (ITS) rRNA gene sequences). A total of 216 bacterial and 98 fungal isolates were obtained using 4 different isolation media. These isolates were identified and belonged to 31 bacterial and 12 fungal species, suggesting an unexpectedly diverse microbial community harbored in the South China Sea gorgonian corals L. rigida and M. kanisa. Furthermore, 56% of the tested microbial isolates displayed various antifouling activities against four biofouling organisms (including two microfouling bacteria Micrococcus luteus and Shewanella onedensis, and two macrofouling organisms Bugula neritina and Balanus amphitrite). Among the microbial isolates with antifouling activity, Bacillus firmus SCAU-038 and Streptomyces parvulus SCAU-062 displayed moderate or strong antifouling activity against all tested biofouling organisms. This is the first study on the biodiversity and antifouling activity of microorganisms associated with gorgonians L. rigida and M. kanisa from the South China Sea. These results contribute to the further understanding of microorganisms associated with gorgonian corals and provide potential resources for new natural antifouling agents.

Effects of Plant Growth-promoting Microorganisms on the Early Growth of Kentucky Bluegrass under Drought and Salinity

Drought and salinity affect turfgrass growth and development adversely. Plant growth-promoting microorganisms (PGPMs) have been shown to have the capability of improving resistance to biotic stressors in plants. The objective of this research was to determine the efficacy of six commercial PGPMs on enhancing the drought and salinity resistance of kentucky bluegrass (Poa pratensis). The six PGPMs evaluated were Beauveria bassiana (strain GHA), Bacillus subtilis (strain GB03), Azadirachtin, Bacillus firmus (strain 1-582), Trichoderma harzianum Rifai (strain T-22) combined with Trichoderma virens (strain G-41), and Bacillus subtilis (strain QST713). Three cultivars—Kenblue, Moonlight, and Waterworks—were seeded in the greenhouse. Two-week seedlings were exposed to saline (sodium chloride at 6 dS⋅m–1 three times per week) or drought (tap water once per week) conditions, and no stress (irrigated with tap water three times per week) for 4 weeks. Results show that drought and salinity inhibited turf growth, with the greatest reduction in root dry weight (50.3% in drought conditions and 31.4% in saline conditions). ‘Kenblue’ performed better than ‘Waterworks’ and ‘Moonlight’ in all growth indices except for root length. Beauveria bassiana and B. subtilis had a similar or better result in enhancing turfgrass growth and development compared with the untreated turf under stress. Our results suggest that certain PGPMs have the potential to improve abiotic stress resistance in turfgrass.

Біологічний захист рослин в Європейському Союзі (на прикладі Німеччини)

The application of ecological plant protection products against diseases, pests, and weeds is relevant for modern science-provided crop production. Much attention is paid to this problem in the European Union, where the use of pesticides is strictly adjusted by the European Food Safety Authority. Great hopes are pinned on biological plant protection products. However, among the thousands of biological products included in the BioPesticide DataBase, only a small number are authorized for use in agriculture. The requirements for the use of biological protectants in organic farming are even more stringent, regulating not only the properties of the product but also the crops in which they can be used. The aim of the work was to present the main requirements for the safety of biopesticides in the EU countries and to give an overview of biopesticides authorized for use in traditional and organic farming using Germany as an example. Methods. Analysis of EU documents on the requirements for registration of active substances in biological products for plant protection, biopesticide databases, and the list of biopesticides approved for use in general and organic farming in Germany. Results. According to the EU requirements for biopesticide safety, registration of biological plant protection products based on bacteria, fungi, and viruses, individual microbial cellular components or metabolites, as well as insect predators, pheromones, and plant-origin substances is allowed. Among the biopesticides with bactericidal and fungicidal effects registered in Germany, the preparations based on microbial antagonizing plant pathogens are prevalent, as well as preparations elaborated on the fungus Aureobasidium pullulans, Trichoderma asperellum, Verticillium albo-atrum, Coniothyrium minitans, bacteria Pseudomonas chlororaphis, Bacillus amyloliquefaciens, and also the preventive drug Cerevisan based on the cell walls of Saccharomyces cerevisiae. The following bioformulations based on Bacillus thuringiensis, Beauveria bassiana, Cydia pomonella Granulovirus, avermectin antibiotic Abamectine A, herbal products Azadirachtin A and Piretrin, and Maltodextrin are registered as insecticides. A bioformulation based on Bacillus firmus is authorized for use as a nematocide. Conclusions. Registration of biological plant protection products in Germany is carried out in accordance with the EU requirements for the safety of biopesticides. The list includes preparations based on antagonistic microorganisms, predatory microorganisms, microbial metabolites with antibiotic activity, substances for stimulation in plants nonspecific resistance to infectious agents. The fungicidal products are the widest represented. The number of products to control bacterial and nematode infections as well as the bioinsecticides spectrum is very limited. These are the well promising areas for further research and development of biological products.

Rice Weevil (Sitophilus oryzae L.) Gut Bacteria Inhibit Growth of Aspergillus flavus and Degrade Aflatoxin B1.

In this study, bacteria residing in the gut of the rice weevils (Sitophilus oryzae L.) (Coleoptera: Curculionidae) feeding on aflatoxin-contaminated corn kernels were isolated and evaluated for their ability to suppress Aspergillus flavus and to remove/degrade aflatoxin B1 (AFB1). Four morphologically distinct S. oryzae gut-associated bacterial isolates were isolated and identified as Bacillus subtilis (RWGB1), Bacillus oceanisediminis (RWGB2), Bacillus firmus (RWGB3), and Pseudomonas aeruginosa (RWGB4) based on 16S rRNA gene sequence analysis. These bacterial isolates inhibited A. flavus growth in the dual culture assay and induced morphological deformities in the fungal hyphae, as confirmed by scanning electron microscopy. All four bacterial isolates were capable of removing AFB1 from the nutrient broth medium. In addition, culture supernatants of these bacterial isolates degraded AFB1, and the degradation of toxin molecules was confirmed by liquid chromatography-mass spectrometry. The bacterial isolates, B. subtilis RWGB1, B. oceanisediminis RWGB2, and P. aeruginosa RWGB4, were capable of producing antifungal volatile organic compounds that inhibited A. flavus growth. These results suggest that the bacterial isolates from S. oryzae gut have the potential to bind and/or degrade AFB1. Further research on their application in the food and feed industries could enhance the safety of food and feed production.

Potential Role of the Yeast Papiliotrema terrestris Strain PT22AV in the Management of the Root-Knot Nematode Meloidogyne incognita

The nematicidal potential of the yeast Papiliotrema terrestris strain PT22AV (YSY) was investigated against the root nematode (RKN) Meloidogyne incognita in in vitro bioassays on infective juveniles (J2) and experiments on tomatoes in pot and greenhouse conditions. The J2 nematodes were exposed to YSY solutions for 19 days, using abamectin (ABA), fosthiazate (FOS) and distilled water as controls. In the experiments on potted and greenhouse tomatoes, 0.5 and 1 kg ha−1 doses of YSY were tested in comparison to ABA, biocontrol agents Purpureocillium lilacinus strain 251 (PUL) and Bacillus firmus strain 1-1582 (BAF), a plant biostimulant/fertilizer (ERG) and the nematicide Fluopyram (FLU). J2’s viability was affected by YSL after 7 days, decreasing to zero on the 15th exposure day, while ABA and FOS resulted in 83 and 100% J2 mortality within 24 h. Only the 1.0 kg ha−1 dose of YSY was able to significantly reduce the final nematode population in soil and gall formation on tomato roots, without significant differences from PUL and BAF. All treatments in comparison also resulted in a significant increase in tomato growth and crop yield, except for 0.5 kg ha−1 of YSY. Data indicated that YSY could represent an additional tool for organic and integrated RKN management.

CULTURABLE ENDOSYMBIOTIC BACTERIA FROM THE INDIAN LAC INSECT, KERRIA LACCA (KERR)

The Indian lac insect, Kerria lacca (Kerr) (Coccoidea: Tachardiidae) is a commercially important phytosuccivorous and sessile scale insect. Lac insects are cultured on suitable host plants in India and some Southeast Asian countries to produce lac. The lac insect harbours a number of endosymbionts. Isolation of culturable microbial endosymbionts and their identification through 16S rRNA has revealed sex and host-related differences of microbial species. Bacillus boroniphilus, Enterobacter cloacae and Staphylococcus sp. were found only in the lac insects reared on the plant host Cajanus cajan, whereas Bacillus firmus, Lysinibacillus xylanilyticus, Bacillus horneckiae and Bacillus velezensis were recorded only from Flemingia macrophylla. B. firmus and L. xylanilyticus were female-specific and B. horneckiae and B. velezensis were male-specific with Flemingia macrophylla as host; E. cloacae was female-specific and Bacillus boroniphilus and Staphylococcus sp. were male specific with C. cajan. Biochemical characteristics of the isolates, their genetic relationship with their taxonomic kin and their probable role, based on the information available about these endosymbionts in other hosts, have been studied.

The discrepant metabolic pathways of PAHs by facultative anaerobic bacteria under aerobic and nitrate-reducing conditions

Studies regarding the facultative anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) were still in the initial stage. In this study, a facultative anaerobe which was identified as Bacillus Firmus and named as PheN7 was firstly isolated from the mixed petroleum-polluted soil samples using phenanthrene and nitrate as the solo carbon resource and electron acceptor under anaerobic condition. The degradation rates of PheN7 towards phenanthrene were detected as 33.17 μM/d, 13.81 μM/d and 7.11 μM/d at the initial phenanthrene concentration of 250.17 μM with oxygen, nitrate and sulfate as the electron acceptor, respectively. The metabolic pathways toward phenanthrene by PheN7 were deduced combining the metagenome analysis of PheN7 and intermediate metabolites of phenanthrene under aerobic and nitrate-reducing conditions. Dioxygenation and carboxylation were inferred as the initial activation reactions of phenanthrene degradation in these two pathways. This study highlighted the significance of facultative anaerobic bacteria in natural PAHs biodegradation, revealing the discrepant metabolic fates of PAHs by one solo bacteria under aerobic and anaerobic environments.

Screening of Antimicrobial Producing Bacteria from Berawe Beach Sand on Kampai Pangkalan Susu Island against Pathogenic Bacteria

Sand is naturally a place to live, grow and develop some marine animals and microorganisms, usually bacteria originating from the sea area that have a large number of bioactive compounds that can produce various kinds of secondary metabolites for further production of antimicrobials. The purpose of this study was to obtain bacteria that have the potential to produce antimicrobials and to characterize bacterial isolates on the sand of Berawe Beach, Kampai Island, Pangkalan Susu. In this study several stages were carried out, namely sampling, isolation, purification, morphological characterization, antimicrobial activity test, gram staining, biochemical test and determining the bacterial genus. The results of this study obtained 9 isolates (SP14A. SP15A, SP16A, SP24A, SP24B, SP35A, SP44A, SP44B and SP45A) which have the potential as antimicrobial producers. Characterization of antimicrobial bacterial isolates from the sand of Berawe Beach, Kampai Island, Pangkalan Susu, namely isolate SP14A, which is a gram- positive bacterium in the form of streptobacilli. SP15A, SP24B and SP44B isolates were coccus-shaped gram-positive bacteria. SP16A, SP35A, SP44A and SP45A isolates were gram-positive bacteria in the form of bacilli. And isolate SP24A is a gram-negative bacterium in the form of streptobacilli. All isolates produce catalase enzymes but do not use carbon and energy. Isolates that are motile (SP14A, SP15A, SP16A, SP24A, SP35A, SP44A and SP45A) can ferment glucose while non-motile (SP24B and SP44B) cannot ferment glucose. These bacteria come from the genera Bacillus, Micrococcus, LactoBacillus and Alcaligenes. Species of Bacillus pumilus, Bacillus subtilis, Bacillus firmus, LactoBacillus bulgaricus, Micrococcus luteus and Alcaligenes eutrophus.

Utilization and transformation of Chrysotila dentata-derived dissolved organic matter by phycosphere bacteria Marinobacter hydrocarbonoclasticus and Bacillus firmus.

The dissolved organic matter (DOM) released from the cocoolithophores (Chrysotila dentata) was studied in laboratory experiments after co-culturing C. dentata with bacteria. Marinobacter hydrocarbonoclasticus (CA6)-γ-Proteobacteria and Bacillus firmus (CF2) were used to investigate the utilization and processing of the DOM derived from C. dentata, utilizing fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (EEM-PARAFAC), while measuring algal abundance and photosynthetic parameters. The experimental groups consisted of axenic C. dentata groups, filter cultured with bacteria (CA6 or CF2) groups, C. dentata co-cultured with bacteria (CA6 or CF2) groups and axenic bacteria (CA6 or CF2) groups. We then evaluated the processing of DOM by determining four fluorescence indices. The number of C. dentata cells and the photosynthetic capacity of microalgae were enhanced by CA6 and CF2. The main known fluorophores, including humic-like components and protein-like components, were present in all sample. The protein-like component of algal-bacterial co-cultures was effectively utilized by CA6 and CF2. The humic-like components increased at the end of the culture time for all cultures. Meanwhile, the average fluorescence intensity of protein-like in CA6 co-culture with algae was lower than that in CF2 co-culture with algae over time. On the other hand, the average fluorescence intensity of humic-like in CA6 was higher than CF2. However, the total change in fluorescence in humic-like and protein-like of axenic CF2 cultures was lower than that of CA6. Hence, the ability of CA6 to transform microalgal-derived DOM was superior to that of CF2, and CF2's ability to consume bacterial-derived DOM was superior to that of CA6.

Exploration The Candidates of Xenobiotic Degrading Indigenous Bacteria from Probolinggo City Landfill by Using Next Generation Sequencing (NGS)

Soil bacteria from tropical environments play a significant role in resolving various environmental issues, including biodegradation. Exploratory research on biodiversity is crucial to develop and harness the potential of different types of soil bacteria that are highly abundant. The bacterial diversity in landfills is typically high due to the decomposition of organic and inorganic waste, creating a favorable medium for the growth and development of soil bacteria. This study aims to assess the candidates of xenobiotic degrading indigenous bacteria from the Probolinggo City landfill using Next Generation Sequencing (NGS) method. The research stages include: 1) sampling, 2) isolation of genomic DNA from samples using the ZymoBIOMICS DNA MiniPrep Kit from Zymo Research, 3) amplification of isolated DNA with primers 16S 27F – 1429R, 4) sequencing the results of DNA amplification with NGS, 5) downstream analysis of the results using software Pavian Krona Tools, and 6) narrative analysis review to identify the candidates of xenobiotic degrading indigenous bacteria. The results show that soil samples from the Probolinggo City landfill exhibited a high diversity of bacterial communities. Based on NGS analysis, 2400 bacterial species were identified, comprising 56 genera, 17 orders, 4 classes, and 4 phyla, with respective abundances of Proteobacteria (70%), Firmicutes (15%), Planctomycetes (2%), and Cyanobacteria (0,3%). Based on the narrative analysis review, several bacteria in the Probolinggo City landfill exhibited potential as: 1) polypropylene-degrading bacteria, including Bacillus cereus, B. licheniformis and B. thuringiensis. 2) styrofoam degrading bacteria, namely Bacillus amyloliquefaciens, Bacillus cereus, Bacillus firmus and Pseudomonas aeruginosa. 3) total ammonia nitrogen (TAN) reducing bacteria, including Bacillus megaterium. 4) pesticide degrading bacteria Profenofos and Chlorantraniliprole, including Bacillus stearothermophilus. and 5) tannic acid degrading bacteria, including Pantoea dispersa. These results indicate that the Probolinggo City landfill is a good habitat for various xenobiotic-degrading bacteria, then the isolation of specific bacteria can be designed using an appropriate selective medium.

"Revealing the genetic arsenal of Bacillus firmus TNAU1: Unleashing nematicidal and plant growth promotion traits"

Bacillus firmus is a promising nematicidal bacterium that also confers plant growth promotion, nutrient acquisition and antimicrobial activities. In the present study, attempts were made for whole genome sequencing of B. firmus TNAU1 isolated from the rhizosphere region of cucumber. The results confirmed that the isolate was B. firmus which contained a single circular genome of 5,370,919 bp (5.3 Mb) in length with an average GC content of 41.16 %. Annotation was performed using PATRIC tool to explore the subsystem analysis, specialty genes, Enzyme Commission (EC) numbers, Gene Ontology (GO) mappings, KEGG pathways of B. firmus TNAU1. A total of 5804 coding sequence (CDS) genes that encode proteins were predicted based on the KEGG and clusters of orthologous groups (COGs) database. Comparative genomic analysis was performed to discover the unique features and their relationship with other available B. firmus strains. Blastp analysis revealed that TNAU 1 genome assemblies had 26 homologs corresponding to nematode-virulent proteases and various genes responsible for plant growth promotion which includes indole acetic acid (IAA) production, nitrate transport, phosphorus and potassium solubilization. Four secondary metabolite biosynthetic clusters encoding antibiotics and siderophore production were confirmed through comparative genomics. B. firmus TNAU1 was evaluated for its antagonistic activity against root-knot nematode Meloidogyne incognita of tomato. The results exhibited that B. firmus inhibited the egg hatching and mortality of juveniles by 96% over control under in vitro conditions and greenhouse experiments confirmed that the TNAU1 strain not only had the potential to suppress the soil and root population of M. incognita (70% reduction over control), but also triggered the plant growth parameters of tomato.

Phenol Biodegradation by some Bacterial Species Isolated from Oil Contaminated Environments

Phenols are poisonous chemical molecules that affect human and other mammals as well as the aquatic environment, particularly higher species in fresh water environments. useing microorganisms through bioremediation is an efficient technique for reducing dangerous chemicals and detoxification of soil contaminated with hydrocarbons. The aim of this study is to investigate the efficiency of some local bacterial species to degrade phenol. Bacterial species were isolated from soils contaminated with hydrocarbons from Al-Diwaniyah and Al-Basrah governorates. The remaining concentration of phenol was examined usingthe 4-aminoantipyrine assay. The results showed that the rate of decomposition of Enterobacter cloacae complex was 100% after an incubation period of 120h, pantoea spp was 100% after an incubation period of 120h, Acinetobacter lwoffii was 100% after an incubation period of 144h, Aeromonas salmonicida was 100% after an incubation period 168h, Escherichia hermannii was 100% after an incubation period of 168h, Sphingomonas paucimobilis was 100% after an incubation period of 168h, Streptococcus thoraltensis was 100% after an incubation period of 168h, Bacillus licheniformis was 97.98%after an incubation period of 168h, Bacillus subtilis was 95.91% after an incubation period of 168h, and Bacillus firmus was 70.91% after an incubation period of 168h. The tested bacterial strains can offer a potential basis for bioremediation of phenol polluted locations.

Impact of biological seed treatments on maize (Zea mays L.) and soil: Crop growth and yield

AbstractSeed treatments have been used since the 17th century, but interest has accelerated in the last 20 years due to our increased understanding and importance of the plant microbiome. Particularly, biological seed treatments (BST) have rapidly gained popularity because soil biota is critical to plant health. Despite growing interest and an expanding market, we still lack understanding of what conditions BST are most effective for plant health. The objective of this study was to understand if seed treatments (including BST) will increase maize (Zea mays L.) growth and grain yield. Here, we tested (1) four maize hybrids and (2) five seed treatments (untreated control [UTC], base fungicide control [BFC], BFC + Poncho [P5] [Clothianidin], BFC + Poncho Votivo [P5V] [Bacillus firmus I‐1582], BFC + Poncho Votivo + TWO.O [P5V2] [Bacillus firmus I‐1582 plus Bacillus thuringiensis EX297512]) across four site‐years. Both BFC and BST had little effect on normalized difference vegetation index (NDVI), plant height, and lodging. We did find a variable effect of BST on maize yield, with a significant site‐year × hybrid interaction (p = 0.06). For instance, in 2019 in Northwest Iowa, both BST treatments (P5V and P5V2) increased yield by an average of 1.5 Mg ha−1 compared to the control (+12%, p < 0.032). BST can improve maize yields, but complex hybrid‐BST interactions warrant further understanding in order to maximize the benefit of BST.

Isolation and Identification of Bacteria from Soil Contaminated With Textile Dye And Tannery Effluents In Sokoto Metropolis

Soil contamination by textile and tannery effluents is a great concern to the environment, Complex effluents having a number of dyes accumulate in the soil there by polluting the environments and loss of microbial species in the soil. Samples were collected and the physicochemical analyses was determined. The pH was basic with 8.0 and 10.1 from tannery and dyeing site respectively. The organic carbon was very low with 0.76% and 0.06%, Nitrogen (0.067% and 0,095%), phosphorus 0.8mg/kg, and 1.62mg/kg), calcium (1.35mol/kg in both the two samples. Magnesium recorded 0.30mol/kg and 1.65mol/kg, potassium 0.85 mol/kg1.65mol/kg , Sodium 3.13mol/kg and 30.0 mol/kg in tannery and dyeing site respectively. The sand, silt and clay recorded (78.8% and 90.6%)(7.3% and 5.3%), (13.9% and 4.1%). The heavy metal content of the soil sample were determined the concentration of chromium was 0.0258 and 0.0043 from tannery and dyeing site respectively, while Nickel was almost unavailable in the site with -1.0700 and -1.0756. Lead recorded a very low concentration with -0.9164 and -7803. Thirteen bacterial species were isolated and identified based on morphology and biochemical charachteristics from the samples, tannery soil with frequency occurrences of 23.07% for Bacillus laterosporus, 15.38% for Bacillus subtilis and Bacillus megaterium while Bacillus firmus, Bacillus cereus, proteus vulgaris, proteus mirabilis and clostridium had 7.69% each. Fifteen species were isolated from the dyeing soil sample with Bacillus subtilis, Bacillus megaterium, and Pseudomonas aeruginosa with the highest frequency of occurrences with13.33% each. Burkholderia cepacia, P. florescense, Bacillus laterosporus,Bacillus amyloliquifeciens, Bacillus brevis and Proteus vulgaris had 6.66% each, all these were determine with the use of Microgen identification kit, molecular analysis was done on two bacterial isolates and were confirmed to be Alishwanella solinqauinati and Bacillus subtilis. These indicate that the species isolated can resist high amount of toxic chemicals and can withstand any harsh environment and hence their ability to serve as a potential biosorbents for bioremediation of the affected environments at a cheap cost.

Biodegradation of di-2-ethylhexyl phthalate by Bacillus firmus MP04 strain: parametric optimization using full factorial design.

Di-2-ethylhexyl phthalate (DEHP) is used as a plasticizer in making plastics and released from landfills. This study attempted to degrade DEHP using microbial isolates. Isolates of Bacillus spp. were tested for their efficacy in degrading DEHP. Degradation was assessed using liquid chromatography-mass spectrometry (LC-MS). The most efficient DEHP degradation was achieved by Bacillus firmus MP04, which has been identified as Bacillus firmus MP04. This strain was found to use DEHP as the sole source of carbon without carbon source supplementation. Full factorial design was used to optimize the conditions for DEHP degradation which revealed the suitability of pH 7, 5% salt concentration, 20 to 37°C temperature, and yeast extract as a nitrogen source. LC-MS elucidated the possible degradation mechanism via benzoic acid formation. However, prolonged incubation formed a typical compound denatonium benzoate due to reactions with other compounds. As maximum degradation was achieved in 4days, prolonged incubation is not suggested. It can be concluded that new strain Bacillus firmus MP04 is the most efficient strain among all the tested strains for DEHP degradation.

A bottom-up approach to select microbes from textile wastewater for detoxification of aromatic amine and azo dye in a single stage

Biological processes show great promise for treating textile wastewater, but the complexity and high energy needs limit their industrial applications. Complete dye degradation involves physiologically distinct bacteria in a two-stage process. First, anaerobic bacteria cleave azo dyes into hazardous aromatic amines, whereas its further degradation requires aerobic bacteria. We propose strategic microbial selection based on their physiological capabilities while developing a bioremediation design to detoxify aromatic amines and dyes in a single stage. Bacillus firmus PM1, the amine degrader, and Serratia liquefaciens PM2, the helper strain, were isolated from textile wastewater. B. firmus PM1 completely degraded 4-Nitroaniline (4-NA), a common dye intermediate, under a range of physicochemical conditions prevalent in textile effluent viz. varying pH (7–11), oxygen availability (static/shaking), temperature (30–40 °C), and 4-NA concentrations (200–1000 μM). Along with 4-NA degradation (100 %), B. firmus PM1 could also efficiently degrade co-contaminants, aniline (35 %), and phenols (45 %). UPLC, FTIR, and LC-MS analysis suggested that when B. firmus PM1 is used in co-culture with S. liquefaciens PM2, it efficiently mineralizes 4-NA (95 %) and reduces Acid Black 1 (AB1) (80 %) dye both in synthetic and the real textile effluent. Further, the co-culture could also significantly reduce 4-NA and AB1 mixture induced phytotoxicity/cytogenotoxicty in Vigna mungo and Allium cepa. Thus, the study demonstrates a novel bottom-up approach that relies on isolating bacteria degrading the penultimate toxic dye metabolite and developing a co-culture for degrading the parent dye. The study demonstrates that detoxification-centric use of specialized microbes has potential to evolve sustainable industrial practices.

Evaluation of the growth-inducing efficacy of various Bacillus species on the salt-stressed tomato (Lycopersicon esculentum Mill.).

Plants are affected by salt stress in a variety of ways, including water deficiency, ion toxicity, nutrient imbalance, and oxidative stress, all of which can cause cellular damage or plant death. Halotolerant plant growth-promoting rhizobacteria (PGPR) could be a viable alternative for tomato plants growing in arid and semi-arid environments. The aim of this research was to isolate halotolerant plant growth promoting Bacillus sp. to promote tomato (Lycopersicon esculentum Mill.) growth and salt stress resistance. 107 PGPR strains were isolated from the rhizospheres of 'Kesudo' (Butea monosperma Lam.), 'Kawaria' (Cassia tora L.), and 'Arjun' (Terminalia arjuna Roxb.) plants to test their plant growth promoting abilities, including indole-3-acetic acid, phosphate solubilization, siderophore production, and ACC deaminase activity. Five bacterial strains (Bacillus pumilus (NCT4), Bacillus firmus (NCT1), Bacillus licheniformis (LCT4), Bacillus cereus (LAT3), and Bacillus safensis (LBM4)) were chosen for 16S rRNA on the basis of PGPR traits. Compared to PGPR untreated plants, tomato plants developed from PGPR-treated seeds had considerably increased germination percentage, seedling growth, plant height, dry weight, and leaf area. As comparison to PGPR non-inoculated plants, salt-stressed tomato plants treated with PGPR strains had higher levels of total soluble sugar, proline, and chlorophyll as well as higher levels of SOD, CAT, APX, and GR activity. PGPR-inoculated salt-stressed tomato plants had lower MDA, sodium, and chloride levels than non-inoculated plants. In addition, magnesium, calcium, potassium, phosphorus, and iron levels were higher in PGPR treated plants when subjected to salt stress. These results indicate that halotolerant PGPR strains can increase tomato productivity and tolerance to salt stress by removing salt stress's negative effects on plant growth.

Effectiveness of Various PGPR Lineage in Controlling White Rust Diseases and Growth Promotion of Chrysanthemum

Effectiveness of Various PGPR Lineage in Controlling White Rust Diseases and Growth Promotion of Chrysanthemum White rust disease caused by Puccinia horiana is the most destructive disease of Chrysanthemum in Indonesia. There was no available effective control measure against the disease in Indonesia. This research aimed to examine the potency of five strains of plant growth-promoting rhizobacteria (PGPR) for controlling white rust disease on Chrysanthemum under field conditions. Five PGPR strains (Pseudomonas diminuta P14, Bacillus firmus J8, Lysinibacillus fusiformis C71, AKBR, AKS) and one commercially formulated PGPR were used in this study. The research was carried out in farmer fields with a randomized complete block experimental design. PGPR was applied by plant watering using bacterial suspension. All PGPR strains were effective in suppressing the white rust disease incidence and its severity. The most effective PGPR strain to suppress white rust disease was Bacillus firmus J8 and the most effective strain to increase the growth of Chrysanthemum plants was Lysinibacillus fusiformis C71. The five PGPR strains tested and commercial formulation increased the diameter of the flower.

Heavy Crude Oil Biodegradation: Catechol Dioxygenase Gene Copy Number Variation Determination by Droplet Digital Polymerase Chain Reaction

The crude oil reserves in Oman mainly consist of heavy oil. Microbial enhanced heavy oil recovery (MEOR) has been proved to be an efficient technique in the tertiary heavy oil recovery. Five Bacillus species potential for enhanced heavy oil recovery (EHOR) were isolated and the biodegradation ability of these isolates was studied. As heavy crude oil comprises of aromatic hydrocarbons rather than aliphatic ones, the aromatic catabolism gene, catechol 2,3-dioxygenase (C23O) and catechol 1,2-dioxygenase (C12O) were the genes of interest in this study along with the reference gene, 16S rDNA. The copy number variation of these genes was determined using droplet digital PCR (ddPCR). The primers and probes for ddPCR assay were designed targeting these genes. It was observed that the heavy crude oil biodegradation potential of the isolates correlated with the copy number of C23O gene in the microbial genomes. The isolate, Paenibacillus ehimensis BS1 had the highest C23O gene copy number (1.057) followed by Bacillus firmus BG4 (0.895) and Bacillus halodurans BG5 (0.031) as demonstrated by their biodegradation potential. This is one of the few studies deploying ddPCR in the field of heavy crude oil biodegradation by spore forming bacteria.

Isolation and Characterization of Poly-3-hydroxybutyrate (PHB)-producing Bacteria from some Municipal Waste within Maiduguri Borno State Nigeria

The present work was conducted to isolate, screen and identify polyhydroxybutyrate (PHB)-producing bacteria from municipal wastes. Samples were collected from dumping sites of Maiduguri Borno State and were checked for their bacterial population using nutrient agar and PHB Detection agar (PDA). A total of 20 PHB-producing bacteria were isolated and identified. Of the total, four of the isolates were found to be from Paenibacillus spp. while the remaining 16 were Bacillus spp. Isolates from Ngomari Custin denoted as NC 5, 2; NC 7, and NC 5A were suspected to be Paenibacillus favisporus, Bacillus lentus, and Bacillus firmus respectively while others of NC 7A X, NC 6A and NC 7A Y of the same site were all found to be Bacillus smithii. Isolates from Old Maiduguri Graveyard denoted as OMG 5X, OMG 7, OMG 6 and OMG 5A were all found to be Bacillus smithii. The isolates from Flour Mill Area denoted as FMA 5A, FMA 6A, FMA Y, and FMA7B were found to be Bacillus smithii, Paenibacillus nanensis, Bacillus acidiceler and Paenibacillus septentrionalis respectively. On the other hand, isolates from Ramat Square site denoted as RS 6,2; RS 6A, RS 5, RS 7,2 were registered as Bacillus nealsonii, Paenibacillus cookie, Bacillus firmus and Bacillus megaterium respectively. Those of RS 5B and RS 7A of the same sample site were both Bacillus acidiceler and their granules were stained by Nile Blue A staining and observed under the fluorescence microscope and were classified for the extent of their PHB production based on the intensity of fluorescence emitted under the microscopy. NC 7 produced the highest PHB yield compared to all other isolates. Hence, municipal wastes are a rich reservoir of PHB-producing bacteria and can readily produce (PHB), which has enormous advantages over petroleum-based polymers by means of cost effectiveness and eco-friendliness