Thuringiensis Strains Research Articles

EVALUATION OF AZO DYE ORANGE G DECOLORIZATION AND DEGRADATION BY BACTERIA ISOLATED FROM TEXTILE EFFLUENT

The bacteria were isolated and identified from textile effluent, and their ability to decolorize the hazardous azo dye Orange G was evaluated. After incubating the isolates for 24 hours in mineral salt medium supplemented with 100 ppm Direct Orange G, their decolorizing activity was measured spectrophotometrically. Lysinibacillus sp. AUBTP7 (AK1), Bacillus muralis strain1Y118 (AK2), and Bacillus thuringiensis strain N3 (AK3) were identified as the bacterial strains. Bacillus thuringiensis strain N3 (AK3) was the most efficient bacteria at decolorizing Orange G (100ppm), removing 93% of the color in 24 hours at 36ºC temperature. Study of HPLC chromatogram of Orange G and degradation products suggests the formation of new compounds. As a result of this research, it has been revealed that some bacteria live in textile effluents and use dyes as a source of energy and nourishment, implying their usefulness in the treatment of industrial effluents.

Bioactive exopolysaccharide from endophytic Bacillus thuringiensis SMJR inhibits food borne pathogens and enhances the shelf life of foods

In recent times, the use of microbial exopolysaccharides as food preservative has gained significant industrial applications. Accordingly, in this study, EPS producing bacteria was isolated from mango leaf. The isolated bacteria were identified as B. thuringiensis strain SMJR by morphological characteristics and 16s rDNA sequencing. The 16s rDNA gene sequences were submitted to GenBank database under accession number MZ049561. The isolated B. thuringiensis strain SMJR strain was subjected to EPS production using basal salt medium. EPS was recovered and purified by ethanol precipitation. The anthrone test showed that EPS is a polysaccharide composed mainly of glucose. EPS was characterized by UV–Vis spectra and FTIR. UV–Vis spectra showed an absorbance peak at 230 nm indicating the presence of polysaccharides. FTIR revealed the presence of various functional groups stretching between 4000 and 200 cm-1. The antibacterial activity demonstrates that both the crude EPS and pellet possessed inhibitory activities against the tested food borne pathogens (E. coli and K. pneumoniae). The crude EPS showed greater antibacterial effects against the tested food borne bacteria when compared to the pellet. Furthermore, EPS has enhanced the shelf life of grape juice by preventing the growth of pathogenic bacteria. This study concludes that the EPS from B. thuringiensis strain SMJR could be used as a potential preservative to prevent the spoilage of food and emergence of food borne diseases.

The Endophytism of Bacillus thuringiensis in Cotton Plants at Acquisition and Oviposition by Bemisia tabaci

Beneficial microorganisms can be applied on the soil or seeds and can protect plants against insect pests or pathogens. It is known which Bacillus thuringiensis (Bt) strains that, when introduced into the soil can be absorbed by the plant and translocate throughout this with insecticidal activity against insect pests that feed on them. For this reason, the ability of Bemisia tabaci ‘B biotype’ (Hemiptera: Aleyrodidae) to ingest Bt sap was evaluated in cotton plants inoculated with the Bt strain, which encodes the GFP gene, Btk-gfp (B. thuringiensis subsp. kurstaki - green fluorescent protein), and tested for oviposition, comparing untreated plants to those treated with Bt strains. The recovery of Btk-gfp was observed in the plant along with its ability to be acquired by nymphs and adults of B. tabaci. Plants treated with Bt strain S1806 had a lower number of B. tabaci eggs than plants that received only sterile water.

Evaluation of Ceftazidime as an Antibiotic Supplement in Mannitol–Yolk–Polymyxin B Agar Used for Enumeration of Bacillus cereus in Ready-to-Eat Vegetables

The Bacillus cereus group of bacteria, which causes foodborne diseases, can be detected by culture on selective media. However, the presence of competing flora is the most common factor preventing the accurate enumeration of B. cereus on selective agars. In this study, we improved the selectivity of mannitol-yolk-polymyxin B agar (MYPA) and its modified version containing trimethoprim (mMYPA) developed in our previous study by supplementation with ceftazidime (16 μg/mL). Ceftazidime-supplemented MYPA (C-MYPA16) and mMYPA (C-mMYPA16) were evaluated for bacteria recovery and selectivity with three types of ready-to-eat vegetables. Four B. cereus and one Bacillus thuringiensis strains were mixed and artificially inoculated into vegetable salad, radish sprouts, and sprout mix and then recovered on MYPA, mMYPA, C-MYPA16, and C-mMYPA16. In all tested vegetables, mMYPA, C-MYPA16, and C-mMYPA16 culture resulted in similar recovery of B. cereus and B. thuringiensis (P > 0.05), whereas radish sprout and sprout mix colonies grown on MYPA were undistinguishable. C-mMYPA16 was the most selective medium because it eliminated most of the competing flora, especially that in sprouts, without negatively affecting the recovery of B. cereus and B. thuringiensis. Our results indicate that supplementation of mMYPA with ceftazidime may improve the selectivity of this medium for B. cereus and B. thuringiensis in food testing.

Characterization of native Bacillus thuringiensis strains against storage pest Tribolium castaneum (Coleoptera: Tenebrionidae)

Fifty one Bacillus thuringiensis (Bt) like bacteria were isolated from diverse sources, viz. soil, silo dusts, insect cadaver, and phyllosphere and evaluated by feeding bioassays against larvae and adults of coleopteran pest red flour beetle, Tribolium castaneum (Herbst) in Division of Entomology, ICAR-IARI, New Delhi during 2014-15. It is a common pest known for attacking and infesting stored grains or products. Fifteen potential Bt strains were shortlisted on the basis of preliminary screening by single dose assays at 100 μg/g of diet against larvae and adults of T. castaneum. The virulence (LC50) of potential isolates was further assessed. The most effective Bt isolate was VKK-GJ4 (LC50=7.02 μg/g of diet) against neonates followed by VKK-GA6 (LC50=19.03 μg/g of diet) against adults of T. castaneum. Gene profiling of potential Bt strains revealed the presence of cry1, cry3, cry7, cry8, cry9, cry11, cry24 and cry28 gene. However, in three Bt strains, viz. JK-5, Tri5-5 and JKII3-2 no cry gene was found but they showed insecticidal activity against T. castaneum. Thus, quantification of the toxicity by insect bioassay is the only way to assess the potential of a strain for the pest control.

Pathogenic and Spoilage Causing Microorganisms Associated with Traditional Seafood Product Jaadi Manufactured in Southern and Western Coastal Belt of Sri Lanka

Aims: The objective of this study was to investigate on microbial related food safety issues and microorganisms associated with the production of Sri Lankan traditional seafood Jaadi.
 Place and Duration of Study: Food Technology Section, Industrial Technology Institute, Colombo, Sri Lanka, between December 2013 to April 2016.
 Methodology: Seven Jaadi processing centers along the Southern and Western coastal belt of Sri Lanka were evaluated for its compliance to food safety, in terms of environment, processing techniques, hygiene and sanitation, physiochemical and microbiological quality of the final product. 
 Samples drawn from all sites were analyzed for its water activity, salt content, pH and microbiological quality. Microorganisms associated with Jaadi production were isolated in selective media, followed by phenotypical, biochemical and molecular biological characterization.
 Results: The pH, water activity and salt content of Jaadi samples ranged between 3.60-5.85, 0.73-0.82 and 24.82-40.47%, respectively. Thirteen bacterial strains and one fungal strain detected were strains found to be responsible for human pathogenesis and food spoilage. These include, Bacillus cereus strain I (MN726935.1), Bacillus cereus strain II (MN901259.1), Bacillus haikouensis strain I (MN901262.1), Bacillus haikouensis strain II (MN726976.1), Bacillus licheniformis (MN726987.1), Acinetobacter baumannii (MN901499.1), Bacillus pumilus strain I (MN901264.1), Bacillus pumilus strain II (MN901263.1), Bacillus paralicheniformis (MN901167.1), Bacillus thuringiensis strain I (MN901165.1), Bacillus thuringiensis strain II (MN901257.1), Bacillus cereus (MN901161.1), Staphylococcus saprophyticus (MN901156.1) and Trichoderma longibrachiatum (MN907169.1). Presence of such organisms clearly proclaims the poor hygienic practices and risks related to food safety in this traditional processing technology.
 Conclusion: Jaadi processing facilities of Southern and Western coastal belt of Sri Lanka needs scientific and technical knowledge to upgrade their processing in order to assure food safety and product quality.

Identification and characterization of a new cry-like gene found in a Bacillus cereus strain.

Bacillus thuringiensis is the most successful microbial insecticide against different pests in agriculture and vectors of diseases. Its activity is mostly attributed to the Cry proteins expressed during its sporulation phase. However, these proteins are not exclusive to B. thuringiensis. Some cry genes have been found in other Bacillus species, or even in other genera. In this work, cry genes were searched in 223 acrystalliferous bacillaceous strains. From these strains 13 amplicons were obtained, cloned, and sequenced; however, only 6 amplicons tested positive for cry-like genes, and the 6 isolates showed to be the same strain. We report the characterization of an unusual strain of B. cereus (LBIC-004) which is unable to form protein inclusions during the sporulation phase. LBIC-004 showed a high identity to B. cereus using the sequences of 16S rRNA, gyrB and hag genes; in addition, a unique plasmid pattern of the strain was obtained. A 1953-bp cry gene was identified, coding for a 651 amino acid protein with a molecular weight of 74.9kDa. This protein showed a predicted three-domain structure, similar to all Cry proteins. However, the amino acid sequence of the protein showed only 41% identity its highest hit: the Cry8Ca1 protein, indicating the uniqueness of this cry-like gene. It was cloned and transferred into a mutant acrystalliferous B. thuringiensis strain which was used in bioassays against Caenorhabditis elegans, Aedes aegypti, Manduca sexta and Phyllophaga sp. The recombinant strain showed no crystal formation and no toxicity to the tested species.

Comparative genome analysis of Bacillus thuringiensis strain HD521 and HS18-1

Bacillus thuringiensis (Bt) is an important biological insecticide used to management of different agricultural pests by producing toxic parasporal crystals proteins. Strain HD521 has an antagonistic effect against Rhizoctonia solani AG1IA, the causal agent of rice sheath blight. This strain with three cry7 genes can the formation of bipyramidal parasporal crystals (BPCs). BPCs are used for insecticidal activities against Henosepilachna vigintioctomaculata larva (Coleoptera). Strain HS18-1 contains different types of BPCs encoding genes and has effective toxicity for Lepidoptera and Diptera insects. Here we report the whole genome sequencing and assembly of HD521 and HS18-1 strains and analyzed the genome constitution covering virulence factors, types of plasmid, insertion sequences, and prophage sequences. The results showed that the genome of strain HD521 contains a circular chromosome and six circular plasmids, encoding eight types of virulence protein factors [Immune Inhibitor A, Hemolytic Enterotoxin, S-layer protein, Phospholipase C, Zwittermicin A-resistance protein, Metalloprotease, Chitinase, and N-acyl homoserine lactonase (AiiA)], four families of insertion sequence, and comprises six pro-phage sequences. The genome of strain HS18-1 contains one circular chromosome and nine circular plasmids, encoding five types of virulence protein factors [Hemolytic Enterotoxin, S-layer protein, Phospholipase C, Chitinase, and N-acyl homoserine lactonase (AiiA)] and four families of insertion sequence, and comprises of three pro-phage sequences. The obtained results will contribute to deeply understand the B. thuringiensis strain HD521 and HS18-1 at the genomic level.

Characterization of a novel Bacillus thuringiensis toxin active against Aedes aegypti larvae

Some Bacillus thuringiensis (Bt) strains produce dipteran-active toxins and can control larval mosquitoes. We identified a novel mosquitocidal toxin named Xpp81Aa1 with the thioredoxin domain from Bt strain HSY204. This toxin has very little sequence similarity to the three-domain Cry toxin and Cyt toxins and has significant toxicity to Aedes aegypti larvae. A safety assessment indicated that the Xpp81Aa1 toxin has no cytocidal activity against red blood cells and did not induce allergic reactions. The Xpp81Aa1 toxin exhibited a synergistic effect in combination with Cry2Aa and Cry4Aa protein toxins. Thus, the Xpp81Aa1 toxin could be a good candidate for mosquito control applications to reduce the mosquito-borne disease.

Aphicidal activities of Moroccan Bacillus thuringiensis strains against cotton aphid (Aphis gossypii)

The objective of this study was to evaluate the insecticidal effect of toxins from Moroccan Bacillus thuringiensis strains (Berliner) (Bt) on Aphis gossypii (Homoptera: Aphididae). Aphis gossypii is one of the most pests of Moroccan crops. Their management is based traditionally on using chemical products. Some of them are well known to be potentially toxic to the environment and human health. Therefore, alternative strategies for aphid management in crops have been developed in recent years, including a biological control using toxins of bacterial strains. In this study, the artificial diet bioassay was used to screen the aphicidal effect of 82 Bt toxins against first instar nymphs and third instar nymphs of A. gossypii. Among the examined Bt strains, eleven showed a high insecticide activity against A. gossypii stages. In addition, the assessment of the lethal concentration (LC50) of selected Bt revealed that the local BtA4, BtA1 and Bt21.6 exhibited higher insecticidal activity against first instar nymphs of A. gossypii (LC50 (BtA4)=0.15, LC50 (BtA1)=0.23 and LC50 (Bt21.6)=0.25 mg/ml) and the selected strains BtB6, BtA10 and Bt21.6 exhibited the relatively best activity third instar nymphs of A. gossypii (LC50 (BtB6)= 0.48, LC50 (BtA10)= 0.79 and LC50 (Bt21.6)= 1.14 mg/ml) of A. gossypii. Therefore, the results of this study indicate that the selected B. thuringiensis strains have great potential to be used in the integrated A. gossypii management.

Characterization and mosquitocidal potency of a Bacillus thuringiensis strain of rice field soil of Burdwan, West Bengal, India

Bacillus thuringiensis is the most popular mosquitocidal bacteria, strains of which are effective against almost all mosquito larvae. It has host specificity and thus, has no adverse effect on non-target species of the ecosystem. Culex tritaeniorhynchus, a vector of Japanese encephalitis (JE), breeds in vast area of rice fields in Burdwan district of West Bengal, India, which has already confronted JE epidemic.Entomological investigation and ecological studies on this vector mosquito showed that JE epidemic may reoccur anytime in the area. A strain of Bt (BU55) was isolated from rice field soil, efficacy was tested against Cx. tritaeniorhynchus and mosquitocidal role was confirmed against Cx. quinquefascistus also. The LC50 of Bacillus thuringiensis BU55 against Cx. tritaeniorhynchus and Cx. quinquefascistus after 72 h was 8.59 ml (final dose 2.49 x107 CFU/ml) and 7.52 ml (final dose 2.20 x 107 CFU/ml), respectively. Insecticidal crystal protein profile of BU55 produced 136.89, 64.80, 43.45, 33.65 and 26.98 kDa bands. Among them 136.89, 64.29, 26.98 kDa proteins are comparable to actual toxins viz. Cry1Ac (138.3 kDa, Lepidoptera specific), Cry4D (68.0 kDa, Diptera specific) and Cyt (27.4 kDa, Diptera specific). The results clearly showed that the Bt strain is a potent dipteran larvicide and can be used against the JE vectors to control the disease.

Parasporin A13-2 of Bacillus thuringiensis Isolates from the Papaloapan Region (Mexico) Induce a Cytotoxic Effect by Late Apoptosis against Breast Cancer Cells

The protein A13-2 was obtained from Bacillus thuringiensis strains isolated from the Papaloapan watershed region (Oaxaca, Mexico). The cytotoxic activity of parasporal inclusions was studied against breast cancer cell line (MCF-7) and normal cell (human peripheral blood mononuclear cells). The MTT, the formation of reactive species, nitric oxide, free cell DNA, and the type of death cellular were assessed. The protein A13-2 shows the highest cytotoxic activity against MCF-7 (13% cell viability at 6 µg/mL), the extracellular DNA increases, and it shows no stress for reactive species or nitric oxide. Besides, the A13-2 parasporin shows no toxicity to peripheral blood mononuclear cells, and it does not generate changes in nitric oxide levels or free cell DNA. Due to that, the cytotoxic effect of A13-2 was specific for MCF-7, and it does not affect normal cells. According to microscopy and flow cytometry, A13-2 parasporin leads to the death of MCF-7 cells by late apoptosis together with necrosis and without allowing the triggering of the survival mechanisms. When analyzed together, our results show for the first time that the A13-2 protein isolated from Mexican strains of B. thuringiensis preferentially kills MCF- 7 (cancer cells) over HEK 293 and PBMC cell lines (normal cells), thus representing a promising alternative for the treatment of cancer breast.

The Potential Activities of Two Bacillus thuringiensis Strains Against the Neonate Larvae of Pectinophera gossypiella

The current study was conducted to investigate the biological activities of the two strains of Bacillus thuringiensis (Bacillus thuringiensis var. Kurstaki 1(Bt K1) and Bacillus thuringiensis var. Kurstaki 2 (Bt K2)) against the newly hatched (neonate) larvae of the pink bollworm, Pectinophera gossypiella. The two strains exhibited their toxicity against the treated larvae. Also, the lethal effect was extended in the resulted stages, pupae and adults. Based on LC50 for total mortality, Bt K1 was more potent than Bt K2 where LC50 was 2.21x1010 and 3.11x1010, respectively. However, the two strains were revealed a reduction of pupation and adult emergence %. Irrespective of the strain, Bt significantly decreased larval duration and significantly increased pupal duration. No effect was recorded on morphogenesis. In the present study,it was broadly that Bacillus thuringiensis showed its ability in the control of Pectinophora gossypiella.

Molecular Characterisation of Soil-Dwelling Bacillus thuringiensis using Transcriptional Regulator, XRE Gene and the Crystal Protein, cry2 gene

Bacillus thuringiensis (Bt) is the organism that is used most frequently in biological pest management, which is distinguished by the capacity to possess crystalline inclusions throughout the sporulation phase. There is an increasing need to use biological control in controlling plant pathogens due to the inherent advantages. However, the detection of Bt has become more time consuming and cumbersome due to the numerous available crystal genes. The goal of the study was to isolate strains of Bacillus thuringiensis from the soil, characterise the isolates using the transcriptional regulator, XRE gene and the crystal proteins cry2gene and compare the efficiency of these two biomarkers in identifying Bt species. Five different Bacillus thuringiensis strains were isolated from soil samples in Zaria, Nigeria. Polymerase chain reaction was used to detect the existence of the cry2 and XRE genes. Four (80%) of the five isolates harboured the XRE genes, while none (0%) harboured the cry2 genes. This observation is a likely indication that the XRE gene is a reliable biomarker in the identification of Bt isolates from environmental samples. In order to ensure speed and reproducibility in the detection of Bt from environmental samples, molecular techniques targeting the XREgene are recommended.

Технологія виробництва біопестицидів на основі Bacillus thuringiensis

Subject of research. Biopesticides are based on live cultures of specially selected beneficial microorganisms with controlled properties. They have a pronounced phytoprotective and stimulating effect, thus providing effective prevention and protection of plants from diseases. The obtained biological product increases productivity, improves the quality and structure of the crop, does not accumulate in plants, which allows to obtain environmentally friendly agricultural products and does not harm the environment. Among the large number of bacteria, as a source of microbiological insecticide is Bacillus thuringiensis, which infects lepidopteran pests and leads to their death. Preparations based on this strain are effective when used in low concentrations of solutions. The Bacillus thuringiensis strain produces several toxins with insecticidal action, including β-exotoxin and δ-endotoxin. Toxic effect is manifested and leads to paralysis of the intestinal tract of parasites. Preparations β-exotoxin and δ-endotoxin are obtained by culturing Bacillus thuringiensis bacteria in a liquid medium. The scientific work proposes a method of industrial production using by-products of vegetable raw materials, which makes it economically feasible to use such substrates. The purpose of the study is the development of technology, formulation of nutrient medium, process parameters for the cultivation of bacteria of the genus Bacillus thuringiensis and obtaining a culture fluid containing substances of the class of biopesticides. Methods. Standard and generally accepted methods of research of bioproducts in biotechnology. The formation of bioinsecticides was established by hydrolysis methods, followed by determination of the component of β-exotoxin – ribose, the formation of octagonal crystals of exotoxin – by microscopic method. Research results. Three variants of nutrient media, which include yeast-polysaccharide complex: corn flour, corn oil, yeast autolysate were developed. The parameters of the bacterial cultivation process were studied. The final product is a paste or powder with a titer of 35 .109 spores in 1 g of the bioproduct. Scope of research results. Microbiological preparations based on Bacillus thuringiensis are highly specific and act only on insect larvae from the classes Lepidoptera and Diptera. The resulting biopesticide can be used against pests of a wide range of vegetable and fruit crops.

Distinctive Molecular typing of 16S rRNA of Bacillus species isolated from farm settlement.

Distinctive Molecular typing of 16S rRNA of Bacillus species isolated from farm settlement.

Genomic Exploration of Bacillus thuringiensis MORWBS1.1, Candidate Biocontrol Agent, Predicts Genes for Biosynthesis of Zwittermicin, 4,5-DOPA Dioxygenase Extradiol, and Quercetin 2,3-Dioxygenase.

Many strains from Bacillus thuringiensis are known for their genomic robustness and antimicrobial potentials. As a result, the quest for their biotechnological applications, especially in the agroindustry (e.g., as biopesticides), has increased over the years. This study documents the genome sequencing and probing of a Fusarium antagonist (B. thuringiensis strain MORWBS1.1) with possible biopesticidal metabolite producing capacity from South Africa. Based on in vitro evaluation and in silico antiSMASH investigation, B. thuringiensis strain MORWBS1.1 exhibited distinctive genomic properties that could be further exploited for in planta and food additive production purposes.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Isolation of Iranian Bacillus thuringiensis strains and characterization of lepidopteran-active cry genes

BackgroundInsecticidal crystal proteins (encoded by cry genes) produced by Bacillus thuringiensis (Bt) are fatal for insects of different orders such as Lepidoptera. The genes that encoded these crystal proteins can be detected on plasmids and chromosomal DNA and show different types in various strains. Therefore, the objective of this study was to determine molecular characteristics of Iranian Bt strains as well as their toxicity against Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae).ResultsThe collection sites included fields, gardens, and desert and semi-desert areas in 8 provinces of Iran. For crystal formation, each isolate was cultured in T3 medium. The results showed that the Bt isolates produced different types of crystals including spherical (73.33%), bipyramidal (53.33%), irregular (40%), cubical (33.33%), and elliptical (13.33%). Plasmid DNA extraction was performed and showed that most of the strains exhibited similar pattern in the number and the size of the plasmid bands to those of Bt kurstaki (Btk). Some specific primers were used for PCR amplification to distinguish different crystal genes including cry1 (A, C, and D) and cry2A (a and b). The primers related to cry1D and cry2Aa1 genes produced no amplicons. The results revealed that the most abundant gene was cry1-type. All strains analyzed for the cry2Ab2 gene presented unexpected bands. Electrophoretic profile of the protein crystals showed bands with different diversity in number, and size ranged from about 16 to 140 KDa. The bioassay result of some more toxic strains exhibited that the pathogenicity of 1019 was higher than the rest, even the reference strain, Btk. However, the toxicity of other strains was the same as Btk. According to the phylogenetic tree, 1019 was located in the same group with Bt subspecies coreanensis, Bt subspecies indiana and Bt subspecies tolworthi.ConclusionsThe investigated Iranian strains had the lepidopteran-active cry genes. The strains with the same toxicity to E. kuehniella had various cry genes, plasmid, and crystal protein profiles and vice versa. Therefore, characterization of cry genes of native strains could lead to access potent isolates as biocontrol agents against native insect pests.

The auxin-producing Bacillus thuringiensis RZ2MS9 promotes the growth and modifies the root architecture of tomato (Solanum lycopersicum cv. Micro-Tom).

Strains of Bacillus thuringiensis (Bt) are commonly commercialized as bioinoculants for insect pest control, but their benefits go beyond their insecticidal property: they can act as plant growth-promoters. Auxins play a major role in the plant growth promotion. However, the mechanism of auxin production by the Bacilli group, and more specifically by Bt strains, is unclear. In previous work, the plant growth-promoting rhizobacterium (PGPR) B. thuringiensis strain RZ2MS9 increased the corn roots. This drew our attention to the strain's auxin production trait, earlier detected in vitro. Here, we demonstrate that in its genome, RZ2MS9 harbours the complete set of genes required in two pathways that are used for Indole acetic acid (IAA) production. We also detected that the strain produces almost five times more IAA during the stationary phase. The bacterial application increased the shoot dry weight of the Micro-Tom (MT) tomato by 24%. The application also modified MT root architecture, with an increase of 26% in the average lateral root length and inhibition of the axial root. At the cellular level, RZ2MS9-treated MT plants presented elongated root cortical cells with intensified mitotic activity. Altogether, these are the best characterized auxin-associated phenotypes. Besides that, no growth alteration was detected in the auxin-insensitive diageotropic (dgt) plants either with or without the RZ2MS9 inoculation. Our results suggest that auxins play an important role in the ability of B. thuringiensis RZ2MS9 to promote MT growth and provide a better understanding of the auxin production mechanism by a Bt strain.

Pseudomonas putida APRRJVITS11 as a potent tool in chromium (VI) removal from effluent wastewater

Bioremediation is an essential feature of microorganisms concerning contaminations in soil and water. The use of microorganisms has been proved to be an effective treatment of industrially released effluents comprising of heavy metals, such as chromium (VI). In the current study, seasonal variations were observed in the concentrations of chromium(VI) as the samples from selected locations showed an increase in mean concentration during the summer compared to the low mean during winter, suggesting excessive evaporation in the summer leading to the heavy metal accumulation. Among the 35 isolates obtained from tannery effluent contaminated wastewater sources the 3 unique strains identified as Streptococcus pyogenes strain APRRJVITS10, Pseudomonas putida strain APRRJVITS11, and Bacillus thuringiensis strain APRRJVITS15, showed tolerance toward chromium(VI) and the maximum tolerance for each strain was 1250 ppm. The media optimization through shake flask methods showed chromium(VI) (in 100 ml LB broth) removal of 47.82%, 48.11%, and 49.93% by S. pyogenes, P. putida, and B. thuringiensis respectively. Further, Pseudomonas putida showed chromium(VI) (in 1500 ml LB broth) removal of 50.48% in optimized conditions, proving to be highly potential for treating effluent wastewater for chromium(VI) removal.