Cereus Strains Research Articles

Isolation and Identification of Four Strains of Bacteria with Potential to Biodegrade Polyethylene and Polypropylene from Mangrove.

With the rapid growth of global plastic production, the degradation of microplastics (MPs) has received widespread attention, and the search for efficient biodegradation pathways has become a hot topic. The aim of this study was to screen mangrove sediment and surface water for bacteria capable of degrading polyethylene (PE) and polypropylene (PP) MPs. In this study, two strains of PE-degrading bacteria and two strains of PP-degrading candidate bacteria were obtained from mangrove, named Pseudomonas sp. strain GIA7, Bacillus cereus strain GIA17, Acinetobacter sp. strain GIB8, and Bacillus cereus strain GIB10. The results showed that the degradation rate of the bacteria increased gradually with the increase in degradation time for 60 days. Most of the MP-degrading bacteria had higher degradation rates in the presence of weak acid. The appropriate addition of Mg2+ and K+ was favorable to improve the degradation rate of MPs. Interestingly, high salt concentration inhibited the biodegradation of MPs. Results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) indicated the degradation and surface changes of PP and PE MPs caused by candidate bacteria, which may depend on the biodegradation-related enzymes laccase and lipase. Our results indicated that these four bacterial strains may contribute to the biodegradation of MPs in the mangrove environment.

Biosynthesis of NiO nanoparticles using Senna occidentalis leaves extract: Effects of annealing temperature and antibacterial activity

In this work a cost effective and ecofriendly green method for the preparation of NiO nanostructures employing Senna occidentalis (S. occidentalis) leaves extract has been reported. XRD studies show that the 400 °C and 500 °C annealed nanostructures were authenticated as pure face centered cubic phase with an average crystallite size are about 27 nm and 15 nm, respectively. The SEM results show that both the annealed samples were nearly spherical with grain sizes ranging between 40 and 700 nm. The band gap of 400 °C and 500 °C annealed NiO nanoparticles (NPs) was estimated to be 5.28 eV and 5.40 eV, respectively from UV-visible studies while the occurrence of Ni-O stretching in the FTIR spectra validates the formation of NiO. Further this work witnesses that the NiO NPs synthesized from the green route offer better antibacterial activity. The observed maximum zone of inhibition of 500 °C annealed NiO NPs was found to be 20 mm and 19 mm for Serratia marcescens and Bacillus cereus strains and indicates that this material can serve as a prospective drug for biomedical application.

Diversity and Prevalence of Indigenous Soil Bacillus spp. in the Major Cabbage Growing Agroecological Zones of Uganda

Different species of genus Bacillus have been reported from different environments of the world. They are reported to play a role of soil fertility improvement, plant growth promotion and disease and pest management. Most of these reports on Bacillus species are from studies conducted outside Uganda and therefore information on the prevalence and diversity of bacillus species in Ugandan soils is scanty. This study aimed at determining the prevalence and diversity of Bacillus spp. isolated from the cabbage rhizosphere in the four major cabbage-growing agroecological zones of Uganda. The experiment was conducted in a laboratory at the College of Veterinary Medicine, Animal Resources and Biosafety Makerere University for morphological and biochemical identification of the Bacillus bacteria. DNA extraction and PCR were conducted at the College of Natural Resources Makerere University while sequencing was done at Macrogen laboratories in Korea and Inqaba Biotec in South Africa. Morphological, biochemical and genomic analyses revealed five Bacillus spp. (22 Bacillus strains) grouped as B. cereus, B. mycoides, B. thuringiensis, B. megaterium and B. bingmayongensis. B. cereus and B. megaterium were the most dominant and widely spread Bacillus spp. A phylogenetic tree indicated three major clads, showing that B. thuringiensis was closely related to B. cereus while B.bingmayongesis was closely related to B.megaterium. The B. mycoides were closely related to some B. cereus strains and B. bingmayongensis. The phylogenetic tree further showed that some Bacillus strains of the same species were distantly related. It was therefore concluded that most abundant and prevalent Bacillus spp. in Ugandan soils were B. cereus and B. megaterium. The presence and abundance of these bacillus species in the Ugandan soil presents an opportunity for soil scientists to innovatively manipulate them for use as biofertilizers and biopesticides for crop production and management. Such innovations would reduce the reliance of farmers on synthetic fertilizers that are pollutants to the environment and unhealthy to the users and consumers

Enhanced production, artificial intelligence optimized three-phase partitioning extraction, and in silico characterization of extracellular neutral Bacillus cereus proteinase

The present study applied atmospheric and room temperature plasma (ARTP) mutagenesis to improve Bacillus cereus strain for neutral proteinase production. The selected improved stable strain, Phe−Tyr-ARTP-60-E demonstrated a 2.88-fold enhanced proteinase yield and 2.81-fold enhanced proteinase activity with shortened fermentation time. An artificial neural network-embedded genetic algorithm (ANN-GA) was employed to optimize the enzyme's three-phase partitioning (TPP) recovery using Python software. The optimized solution of the hybrid model recommended 38.05% wv−1 (NH4)2SO4, 1.0:2.0 crude extract/tert-butanol ratio, pH 5.84 at 23.4 °C, for the exclusive partitioning of proteinase in the intermediate phase, with 202% recovery, 13-fold purity with specific activity of 922 Umg−1. Sensitivity analysis of the model revealed that enzyme recovery was most sensitive to crude extract/tert-butanol ratio with total sensitivity (ST) of 0.253 while purification factor was most sensitive to pH with an ST of 0.444. In silico analysis using Expasy ProtParam tool revealed that mutant proteinase had 3 amino acid substitutions; Val-to-Cys; Val-to-His and Ile-to-Lys, at positions 152, 288, and 292, respectively, and 39.2 kDa molecular weight, 6.42 isoelectric point, and 33.35 instability index. The 3-Dimensional structure of the enzyme predicted by ModWeb v r273 Server revealed 39% sequence identity with Pseudoalteromonas lipolytica thermolysin. The macromolecule increased transmittance in lysozyme-coated contact lenses by 99.6% in 45 min. We conclude that ARTP mutagenesis and ANN-GA optimized TPP are effective and efficient recalcitrant strain improvement and product recovery methods, respectively. Further genetic tools and analysis of the neutral proteinase-producing gene may be required for increased improvement toward sustainable application.

EsxA, a type VII secretion system-dependent effector, reveals a novel function in the sporulation of Bacillus cereus ATCC14579

BackgroundBacillus cereus is a Gram-positive, spore-forming bacterium that produces a spectrum of effectors integral to bacterial niche adaptation and the development of various infections. Among those is EsxA, whose secretion depends on the EssC component of the type VII secretion system (T7SS). EsxA’s roles within the bacterial cell are poorly understood, although postulations indicate that it may be involved in sporulation. However, the T7SS repertoire in B. cereus has not been reported, and its functions are unestablished.MethodsWe used the type strain, B. cereus ATCC14579, to generate ΔessC mutant through homologous recombination using the homing endonuclease I-SceI mediated markerless gene replacement. Comparatively, we analyzed the culture supernatant of type strain and the ΔessC mutant through Liquid chromatography-tandem mass spectrometry (LC-MS/MS). We further generated T7SSb-specific gene mutations to explore the housekeeping roles of the T7SSb-dependent effectors. The sporulation process of B. cereus ATCC14579 and its mutants was observed microscopically through the classic Schaeffer-Fulton staining method. The spore viability of each strain in this study was established by enumerating the colony-forming units on LB agar.ResultsThrough LC-MS/MS, we identified a pair of nearly identical (94%) effector proteins named EsxA belonging to the sagEsxA-like subfamily of the WXG100 protein superfamily in the culture supernatant of the wild type and none in the ΔessC mutant. Homology analysis of the T7SSb gene cluster among B. cereus strains revealed diversity from the 3’ end of essC, encoding additional substrates. Deletions in esxA1 and esxA2 neither altered cellular morphology nor growth rate, but the ΔesxA1ΔesxA2 deletion resulted in significantly fewer viable spores and an overall slower sporulation process. Within 24 h culture, more than 80% of wild-type cells formed endospores compared to less than 5% in the ΔesxA1ΔesxA2 mutant. The maximum spore ratios for the wild type and ΔesxA1ΔesxA2 were 0.96 and 0.72, respectively. Altogether, these results indicated that EsxA1 and EsxA2 work cooperatively and are required for sporulation in B. cereus ATCC14567.ConclusionB. cereus ATCC14579 possesses two nearly identical T7SSb-dependent effectors belonging to the sagEsxA-like proteins. Simultaneous deletion of genes encoding these effectors significantly delayed and reduced sporulation, a novel finding for EsxA.

Draft genome sequence of Bacillus cereus sequence type 2255 isolated from powdered infant formula.

The draft genome sequence of a Bacillus cereus strain, DFPST-SP1, isolated from powdered infant formula in the United States is reported. The 5,216,828-bp draft genome comprises 46 contigs with 66.4× coverage and 36% GC content and was typed as sequence type 2255.

Bacillus cereus CGMCC 1.60196: a promising bacterial inoculant isolated from biological soil crusts for maize growth enhancement.

Soil microbial inoculants are widely recognized as an environmentally friendly strategy for promoting crop growth and increasing productivity. However, research on utilizing the microbial resources from desert biological soil crusts to enhance crop growth remains relatively unexplored. In the present work, a bacterial strain designated AC1-8 with high levels of amylase, protease, and cellulase activity was isolated from cyanobacterial crusts of the Tengger Desert and identified as Bacillus cereus (CGMCC 1.60196). The refinement of the fermentation parameters of B. cereus CGMCC 1.60196 determined that the most effective medium for biomass production was composed of 5 g/L glucose, 22 g/L yeast extract and 15 g/L MgSO4, and the optimal culture conditions were pH 6.0, temperature 37°C, inoculation quantity 3% and agitation speed 240 rpm. Furthermore, the utilization of B. cereus CGMCC 1.60196 has resulted in substantial improvements in various growth parameters of maize seedlings, including shoot length, shoot fresh and dry weights, root fresh and dry weights, and the contents of chlorophyll a, chlorophyll b, and total chlorophyll. The most pronounced growth promotion was observed at an application concentration of 1 × 109 CFU/m2. These results suggest that the novel B. cereus strain, isolated from cyanobacterial crusts, can be regarded as an exemplary biological agent for soil improvement, capable of enhancing soil conditions, promoting crop cultivation and supporting food production.

Feed supplementation with quorum quenching probiotics improved growth response, immune response, and resistance in the giant mottled eel, Anguilla marmorata

This study aimed to evaluate the effect of feed supplementation with quorum quenching (QQ) probiotic bacteria on growth performance, hematology, immune response, and disease resistance in giant mottled eels. The feed used was supplemented with 45 ± 2.3 g/individual QQ bacteria using the following treatments, namely Bacillus cereus strain B8, Pseudomonas putida strain BPA1, Bacillus cereus strain HPC 576, and control (no QQ). A total of 420 eels (average weight 45 ± 2.3 g/ind.) were randomly reared in 12 open tarpaulin ponds of 2 x 1 x 1 (W x L x D) m and 1000-L volume for 8 weeks. Feed was given three times per day at 5% of the body weight. Water was changed daily at 25%, and shelters were provided using 3-inch diameter PVC pipes. The results showed that the feed containing QQ bacteria improved the growth, hematology, immunity, and disease resistance of the eels compared to the control (P < 0.05). Furthermore, among the QQ bacteria tested, the feed with B. cereus strain HPC 576 had the highest performance in all tested parameters.

The megaplasmid pCER270 of Bacillus cereus emetic strain affects the timing of the sporulation process, spore resistance properties, and germination.

The acquisition of new mobile genetic elements, such as plasmids, is essential for the pathogenesis and adaptation of bacteria belonging to the Bacillus cereus group. This can confer new phenotypic traits and beneficial functions that enable bacteria to adapt to changing environments and colonize new ecological niches. Emetic B. cereus strains cause food poisoning linked to the production of cereulide, the emetic toxin whose synthesis is due to the presence of plasmid pCER270. In the environment, cereulide provides a competitive advantage in producing bacteria against various competitors or predators. This study demonstrates that pCER270 also regulates the sporulation process, resulting in spores with improved heat resistance and germination capacity. The transfer of plasmid pCER270 among different strains of the B. cereus group may enhance their adaptation to new environments. This raises the question of the emergence of new pathogenic strains, which could pose a serious threat to human health.

Boronic ester bonds hydrogel with temperature and pH responsiveness for controlled release fertilizer

The growth of plants can be severely restricted by insufficient water and fertilizers in pure soil. There exists a significant demand for developing a hydrogel to enhance water retention and enable control release fertilizer. In this study, we synthesized the boronic ester bonds hydrogel with temperature and pH responsiveness using sodium alginate, borax pentahydrate and carboxymethyl chitosan (CMCS) via a one-pot method. Urea was loaded in the hydrogel as a model fertilizer. The dual responsive hydrogel exhibited a rapid release behavior of fertilizer due to the dissociation of boronic ester bonds at 40 °C and pH 5.5. The incorporation of CMCS improved the non-covalent interaction within the hydrogel, accompanied by a reduction in the pore size and swelling ratio to 74 μm and 11.3 g/g, respectively. The hydrogel exhibited desirable water retention capacity in soil with a weight loss of only 41.9 % at day 15, while the degradation rate of hydrogel was 49.0 %. Additionally, the hydrogel displayed good antibacterial activity against both Rhizobium and Bacillus cereus strains while being non-toxic to plants. The dual responsive hydrogel holds promising applications in agriculture, forestry, and horticulture.

Isolation and characterization of chromium-resistant bacteria and their effects on germination, growth, and Cr accumulation in Capsicum annum (L.) under Cr stress

Chromium (Cr) is a well-known environmental pollutant while less information is available on the role of Cr-resistant bacteria in the alleviation of Cr-stress in chili (Capsicum annum L.) plants. Effect of Cr-resistant bacterial strains on growth and Cr uptake by chili plants was investigated. The results revealed that Cr-stress showed a negative effect on germination, photosynthesis, and relative water content but the inoculation ameliorated the plant stress. Chromium-resistant bacterial strains enhanced the shoot and root growth (33% SL, 19.7% RL), shoot and root dry weight (35%, 32.9%), relative water content (32.25%), membrane stability index (46.52%) SPAD value (50.76%), Cr concentration in shoots and roots (19.87 and 18.52 mg kg−1), bioaccumulation and translocation factor (0.396 mgkg−1), and seedling vigor index (40.8%) of plants. Chromium-resistant bacterial strains enhanced the NPK uptake while reduced Cr uptake by plants. The morphological and biochemical examination of rhizobacterial strains (and NM28) resistant to Cr-stress revealed smooth, off-white colonies of bacteria composed of rod-shaped cells which are Gram positive in reaction while negative in catalase activity. High quantities of malic acid were produced by bacterial strains under study i.e. NM8 (926.12 μgmL−2) and NM28 (992.25 μgmL−2). These strains were identified as Bacillus cereus strain NM8 and Bacillus subtilis strain NM28 through 16S rRNA sequencing. Results showed that B. cereus strain NM28 is more effective than B. cereus strain NM8 in promoting the growth of Cr-stressed Chili that might be suitable to develop biofertilizer for sustainable production of vegetables under metal stress.

Exploring the antimicrobial and antioxidant properties of Lentzea flaviverrucosa strain E25-2 isolated from Moroccan forest soil.

The alarming rise in antimicrobial resistance (AMR) has created a significant public health challenge, necessitating the discovery of new therapeutic agents to combat infectious diseases and oxidative stress-related disorders. The Lentzea flaviverrucosa strain E25-2, isolated from Moroccan forest soil, represents a potential avenue for such research. This study aimed to identify the isolate E25-2, obtained from soil in a cold Moroccan ecosystem, and further investigate its antimicrobial and antioxidant activities. Phylogenetic analysis based on 16S rRNA gene sequences revealed the strain's classification within the Lentzea genus, with a sequence closely resembling that of Lentzea flaviverrucosa AS4.0578 (96.10% similarity). Antimicrobial activity in solid media showed moderate to strong activity against Staphylococcus aureus ATCC 25923, Bacillus cereus strain ATCC 14579, Escherichia coli strain ATCC 25922, Candida albicans strain ATCC 60193 and 4 phytopathogenic fungi. In addition, ethyl acetate extract of this isolate demonstrated potent antimicrobial activity against 7 clinically multi-drug resistant bacteria. Furthermore, it demonstrated antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, as well as a significant increase in ferric reducing antioxidant power. A significant positive correlation was observed between antioxidant activities and total content of phenolic compounds (p < 0.0001), along with flavonoids (p < 0.0001). Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of amines, hydroxyl groups, pyridopyrazinone rings, esters and pyrrolopyrazines. The Lentzea genus could offer promising prospects in the fight against antibiotic resistance and in the prevention against oxidative stress related diseases.

Evaluating the Safety of Bacillus cereus GW-01 Obtained from Sheep Rumen Chyme.

Bacillus cereus is responsible for 1.4-12% food poisoning outbreaks worldwide. The safety concerns associated with the applications of B. cereus in health and medicine have been controversial due to its dual role as a pathogen for foodborne diseases and a probiotic in humans and animals. In this study, the pathogenicity of B. cereus GW-01 was assessed by comparative genomic, and transcriptome analysis. Phylogenetic analysis based on a single-copy gene showed clustering of the strain GW-01, and 54 B. cereus strains from the NCBI were classified into six major groups (I-VI), which were then associated with the source region and sequence types (STs). Transcriptome results indicated that the expression of most genes related with toxins secretion in GW-01 was downregulated compared to that in the lag phase. Overall, these findings suggest that GW-01 is not directly associated with pathogenic Bacillus cereus and highlight an insightful strategy for assessing the safety of novel B. cereus strains.

Isolation and characterization of a novel Bacillus cereus bacteriophage vBce-DP7

Foodborne pathogens have become a major concern for public health. Bacillus cereus, a representative foodborne pathogen, is particularly challenging due to its ability to cause food poisoning and its resilient spores that are difficult to completely eradicate. Therefore, it is crucial to develop measures to prevent and control B. cereus. Bacteriophages, which are high specific towards their host strains and cannot infect eukaryotes, have proven to be effective in combating foodborne pathogens and are safe for human use. In this study, we isolated and characterized a novel bacteriophage named vBce-DP7 that specifically targets B. cereus strains belonging to three different sequence types (STs). Phage vBce-DP7 is a lytic one and has a short latent time of only 15 min. Moreover, it exhibites a good temperature tolerance, retaining high activity across a broad range of 4–55 ℃. Additionally, its activity remains unaffected within a wide pH range spanning from 2 to 10. Interestingly, with only 4 % genetic similarity with known bacteriophages, vBce-DP7 shows a possible classification on a family level though it shares many similar functional proteins with Salasmaviridae bacteriophages. Taken together, vBce-DP7 demonstrates its significant potential for further exploration in terms of phage diversity and its application in controlling B. cereus.

Изменение химического состава и антимикробной активности меда, хранящегося при низких температурах

Natural honey can change its physicochemical and biological properties during storage. According to State Standard 19792-2017, honey should be stored at ≤ 20°C. Some publications promote long-term storage of honey at temperatures between 0 and –20°C that preserves its physicochemical parameters, especially the content of hydroxymethylfurfural. Promising as they seem, such temperature modes may affect other physicochemical parameters of honey. The research objective was to study the effect of different temperature conditions on various honey samples and their physicochemical and biological parameters during long-term storage. The study applied standard and authentic research methods to fresh linden, buckwheat, and sunflower honey samples obtained from Rostov, Volgograd, Kursk, Voronezh, Saratov, and Krasnodar regions. They were stored in heat, cold, and moisture test chambers M-60/100-500 for 12 months. Hydroxymethylfurfural proved stable at –18°C for 12 months. After 12 months at 18°C, it showed a sharp increase of 472.5–488.1%. The activity of enzymic diastase, D-glucose-1-oxidase, and catalase occurred at all temperature modes after 1 month of storage. At 0–5°C, the changes were minimal: hydrogen peroxide (H2O2) remained stable, and its concentration decreased by ≤ 12.2% after 12 months of storage. Moisture, mass fraction of reducing sugars, and acidity remained stable in all samples. An antimicrobial test by Escherichia coli (strain 1257), Staphylococcus aureus (strain 209-P), and Bacillus cereus (strain 96) showed that the best inhibiting properties belonged to the samples of linden and buckwheat honey stored at 5 and 0°C for 12 months. The optimal temperatures for long-term honey storage were in the range between 5 and 0°C. The results obtained can be used in updated honey storage standards.

Applications of bacteriophage in combination with nisin for controlling multidrug-resistant Bacillus cereus in broth and various food matrices

This study focused on the isolation and characterization of bacteriophages with specific activity against toxin-producing and multidrug-resistant strains of Bacillus cereus sensu stricto (B. cereus s. s.). Ten different samples yielded six bacteriophages by utilizing the double-layer agar technique. The most promising phage, vB_BceS-M2, was selected based on its broad host range and robust lytic activity against various B. cereus s. s. strains. The phage vB_BceS-M2 had a circular double-stranded DNA genome of 56,482 bp. This phage exhibited stability over a wide range of temperatures and pH values, which is crucial for its potential application in food matrices. The combined effect of phage vB_BceS-M2 and nisin, a widely used antimicrobial peptide, was investigated to enhance antimicrobial efficacy against B. cereus in food. The results suggested that nisin showed synergy and combined effect with the phage, potentially overcoming the growth of phage-resistant bacteria in the broth. Furthermore, practical applications were conducted in various liquid and solid food matrices, including whole and skimmed milk, boiled rice, cheese, and frozen meatballs, both at 4 and 25 °C. Phage vB_BceS-M2, either alone or in combination with nisin, reduced the growth rate of B. cereus in foods other than whole milk. The combination of bacteriophage and nisin showed promise for the development of effective antimicrobial interventions to counteract toxigenic and antibiotic-resistant B. cereus in food.

Biofilm-forming Ability of Bacillus thuringiensis Strains from Biopesticides on Polystyrene and their Attachment on Spinach

Bacillus thuringiensis-based commercial products as a biopesticide have been used for more than 60 years in agriculture. However, as one of the species in B. cereus group, B. thuringiensis has been considered as an emerging hazard with the potential to cause food toxico-infections. The present study aimed to evaluate the biofilm-forming ability of B. thuringiensis biopesticide strains and their attachment on spinach, compared to foodborne B. cereus strains. Biofilm formations of tested strains were found to be strain-specific and affected by the nutrient conditions more than the incubation time. Nutrient starvation conditions generally reduced the biofilm formation of tested B. thuringiensis and B. cereus strains, particularly B. thuringiensis ABTS-1857 strain was found as the nonbiofilm former in starvation conditions. It is worth mentioning that B. thuringiensis SA-11 strain showed stronger biofilm-forming ability with more air–liquid interface biofilm than the other two B. thuringiensis biopesticide strains, but no such higher attachment of B. thuringiensis SA-11 to spinach was observed. These results indicate that B. thuringiensis SA-11 strain can enter the food processing lines by the attachment on spinach leaves, and it has the potential to form biofilms throughout the processing lines or the production environment when sufficient nutrients are available. However, more biofilm tests of B. thuringiensis biopesticide strains in the vegetable production chain should be performed. The dry formulation of commercial B. thuringiensis biopesticides enhanced their adhesion on spinach leaves, whereas the strength of adhesion was not improved by the formulation. In addition, 1–2 log reductions of spores after the intensive washing of spinach leaves in the lab were detected. However, the log reduction due to the actual washing done by the food processing companies in large-volume washing baths or by consumers at home would be limited and less than this lab simulation.

Optimisation of fermentation conditions for the production of gamma-aminobutyric acid (GABA)-rich soy sauce

This study addresses the challenge of enhancing gamma-aminobutyric acid (GABA) content in soy sauce through optimized fermentation condition. Using a multiple starter culture, consisting of Aspergillus oryzae strain NSK, Bacillus cereus strain KBC and Tetragenococcus halophilus strain KBC, the incubation conditions including the percentage of bacterial inoculum (10, 15 and 20 %), pH (3, 5 and 7) and agitation speed (100, 150 and 200 rpm) were optimized through Response Surface Methodology (RSM). Under the optimal conditions (20 % inoculum, pH 7 and stirring at 100 rpm), the multiple starter culture generated 128.69 mg/L of GABA after 7 days and produced 239.08 mg/L of GABA after 4 weeks of fermentation, which is 36 % higher than under non-optimized conditions (153.48 mg/L). Furthermore, sensory analysis revealed high consumer acceptance of the fermented soy sauce than the control (soy sauce without any treatment and additional bacteria) and commercial soy sauce. Consumers indicated that the starter culture offered an improved umami taste and reduced bitter, sour and salty flavours compared to the commercial product. Under optimal fermentation conditions determined by RSM statistical analysis, the multiple starter culture is able to produce high levels of GABA and is more likely to be accepted by consumers. The findings of this research have the potential to impact the food sector by offering a functional soy sauce with added health benefits and also being well-received by consumers.

Screening of Probiotic Candidates Bacteria as Biocontrol of Aeromonas Hydrophila Pathogen Isolated from Mina Padi Cultivation Area

The agricultural activities in rice-farming system can have an impact on fish farming and the characteristics of bacterial community, especially pathogenic bacteria. Utilization of probiotics as environmentally friendly biotechnology products can be used to improve environmental quality and suppress the presence of pathogenic bacteria. This study aimed to select bacteria as probiotic agents from aquaculture ponds with the Rice-fish farming system. A total of 22 bacterial isolates were isolated from the water and sediment contained in the culture ponds. Based on the screening results, 15 isolates were confirmed as general non-pathogenic bacteria (Aeromonas sp.), 9 isolates had antibacterial activity against Aeromonas hyrophylla and 4 isolates showed high antibiotic sensitivity and were able to synergize. The results showed the Proteus mirabilis, Proteus penneri, Kurthia gibsonii and Bacillus cereus strains. Bacillus cereus strain LB8 has antibacterial activity that can inhibit the pathogen Aeromonas hydrophila with an inhibition zone of 8mm and has a very high sensitivity to antibiotics. These four isolates are able to work together synergistically and can be used as consortium probiotic bacterial agents to suppress the growth of pathogens.

Microbial detoxification of chlorpyrifos, profenofos, monocrotophos, and dimethoate by a multifaceted rhizospheric Bacillus cereus strain PM38 and its potential for the growth promotion in cotton.

Bacillus genera, especially among rhizobacteria, are known for their ability to promote plant growth and their effectiveness in alleviating several stress conditions. This study aimed to utilize indigenous Bacillus cereus PM38 to degrade four organophosphate pesticides (OPs) such as chlorpyrifos (CP), profenofos (PF), monocrotophos (MCP), and dimethoate (DMT) to mitigate the adverse effects of these pesticides on cotton crop growth. Strain PM38 exhibited distinct characteristics that set it apart from other Bacillus species. These include the production of extracellular enzymes, hydrogen cyanide, exopolysaccharides, Indol-3-acetic acid (166.8μg/mL), siderophores (47.3μg/mL), 1-aminocyclopropane-1-carboxylate deaminase activity (32.4μg/mL), and phosphorus solubilization (162.9μg/mL), all observed at higher concentrations. This strain has also shown tolerance to salinity (1200mM), drought (20% PEG-6000), and copper and cadmium (1200mg/L). The amplification of multi-stress-responsive genes, such as acdS, ituC, czcD, nifH, sfp, and pqqE, further confirmed the plant growth regulation and abiotic stress tolerance capability in strain PM38. Following the high-performance liquid chromatography (HPLC) analysis, the results showed striking compatibility with the first kinetic model. Strain PM38 efficiently degraded CP (98.4%), PF (99.7%), MCP (100%), and DMT (95.5%) at a concentration of 300ppm over 48h at 35°C under optimum pH conditions, showing high coefficients of determination (R2) of 0.974, 0.967, 0.992, and 0.972, respectively. The Fourier transform infrared spectroscopy (FTIR) analysis and the presence of opd, mpd, and opdA genes in the strain PM38 further supported the potential to degrade OPs. In addition, inoculating cotton seedlings with PM38 improved root length under stressful conditions. Inoculation of strain PM38 reduces stress by minimizing proline, thiobarbituric acid-reactive compounds, and electrolyte leakage. The strain PM38 has the potential to be a good multi-stress-tolerant option for a biological pest control agent capable of improving global food security and managing contaminated sites.