Paenibacillus Alvei Research Articles

Paenibacillus suaedae sp. nov. and Paenibacillus violae sp. nov., isolated from the roots of Suaeda japonica Makino and Viola mandshurica W. Becker with plant growth-promoting potential.

Two novel Gram-positive strains, chi10T and PFR10T, were isolated from the roots of Suaeda japonica Makino and Viola mandshurica W. Becker, respectively. The strains are facultatively aerobic, rod-shaped, motile via peritrichous flagella and endospore-forming. Strains chi10T and PFR10T showed the highest 16S rRNA gene sequence similarity to Paenibacillus alvei DSM 29T (99.0%) and Paenibacillus planticolens LMG 31457T (99.3%). Furthermore, the phylogenetic and phylogenomic analyses demonstrated that strains chi10T and PFR10T were closely related to the genus Paenibacillus. The digital DNA-DNA hybridization (dDDH) values for strains used in the phylogenetic analysis and strain chi10T ranged from 19.6 to 28.4%, while for strain PFR10T, the values ranged from 19.8 to 53.5%, according to the Genome-to-Genome Distance Calculator 3.0, which were all less than 70%. Additionally, the dDDH value between strains chi10T and PFR10T was 22.0%, confirming that they are different species of the genus Paenibacillus. The average nucleotide identity between chi10T and PFR10T and other species of the genus Paenibacillus were 68.4-84.7% and 67.8-93.6%, respectively. In addition, the major polar lipids of chi10T and PFR10T consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acid profile of strain chi10T was iso-C15 : 0 and anteiso-C15 : 0, whereas the major fatty acid profile of strain PFR10T was iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. The sole respiratory quinone in strains chi10T and PFR10T was menaquinone-7. Phylogenomic, phenotypic and genome analyses strongly indicated that chi10T and PFR10T could be two novel Paenibacillus species for which the names Paenibacillus suaedae sp. nov. (type strain chi10T = KACC 23258T = TBRC 17803T) and Paenibacillus violae sp. nov. (type strain PFR10T = KACC 23263T = TBRC 17804T) are proposed, respectively.

Influence of Soil Phosphate on Rhizobacterial Performance in Affecting Wheat Yield

As a primary nutrient in agricultural soils, phosphorus plays a crucial but growth-limiting role for plants due to its complex interactions with various soil elements. This often results in excessive phosphorus fertilizer application, posing concerns for the environment. Agri-research has therefore shifted focus to increase fertilizer-use efficiency and minimize environmental impact by leveraging plant growth-promoting rhizobacteria. This study aimed to evaluate the in-field incremental effect of inorganic phosphate concentration (up to 50 kg/ha/P) on the ability of two rhizobacterial isolates, Lysinibacillus sphaericus (T19), Paenibacillus alvei (T29), from the previous Breedt et al. (Ann Appl Biol 171:229–236, 2017) study on maize in enhancing the yield of commercially grown Duzi® cultivar wheat. Results obtained from three seasons of field trials revealed a significant relationship between soil phosphate concentration and the isolates’ effectiveness in improving wheat yield. Rhizospheric samples collected at flowering during the third season, specifically to assess phosphatase enzyme activity at the different soil phosphate levels, demonstrated a significant decrease in soil phosphatase activity when the phosphorus rate reached 75% for both isolates. Furthermore, in vitro assessments of inorganic phosphate solubilization by both isolates at five increments of tricalcium phosphate-amended Pikovskaya media found that only isolate T19 was capable of solubilizing tricalcium at concentrations exceeding 3 mg/ml. The current study demonstrates the substantial influence of inorganic phosphate on the performance of individual rhizobacterial isolates, highlighting that this is an essential consideration when optimizing these isolates to increase wheat yield in commercial cultivation.

Valorisation of low-density polythene (LDPE) waste into fuels and chemicals through alkane hydroxylase and microbial treatment

Polythene exhibits low reactivity and slow biodegradability due to its highly reduced hydrocarbon structure. In this study, a process has been developed for the transformation of polythene waste into fuel and its precursor molecule by microbial and enzymatic treatments. In first step polythene was pretreated with Paenibacillus alvei. Through fermentation process for 15 days and products released after fermentation were subsequently bio-transformed into alcohols and acids corresponding to its hydrocarbons, employing Alkane hydroxylase (AlkB). On fermentation using Paenibacillus alvei, 16.8% weight loss was observed after 15 days and surface modification was analyzed through AFM and SEM. The major products released during microbial pretreatment analyzed through Chromatography–High-Resolution Mass Spectrometry (GC-HRMS) were pentane, hexane, heptadecane, dodecane, tetracontane, bromotetradecane, methyl esters, hexadecane, etc. which were converted in second step into hexadecanol, octadecanol, octadecanoic acid, and heptadecanoic acid, etc. with the help of Alkane hydroxylase on enzymatic transformation. These findings suggested that the microbial pretreatment results in a release of alkanes, some fatty acids, and esters using Paenibacillus alvei Among these, AlkB facilitated the transformation of C16 and C15 hydrocarbons into hexadecanol, and pentadecanol respectively. This process holds the potential as an alternative to traditional fuels, and an optimization process can be pursued to enhance the overall yield.

Isolation of delignifying bacteria and optimization of microbial pretreatment of biomass for bioenergy.

Microbial pretreatment of lignocellulosic biomass holds significant promise for environmentally friendly biofuel production, offering an alternative to fossil fuels. This study focused on the isolation and characterization of two novel delignifying bacteria, GIET1 and GIET2, to enhance cellulose accessibility by lignin degradation. Molecular characterization confirmed their genetic identities, providing valuable microbial resources for biofuel production. Our results revealed distinct preferences for temperature, pH, and incubation period for the two bacteria. Bacillus haynesii exhibited optimal performance under moderate conditions and shorter incubation period, making it suitable for rice straw and sugarcane bagasse pretreatment. In contrast, Paenibacillus alvei thrived at higher temperatures and slightly alkaline pH, requiring a longer incubation period ideal for corn stalk pretreatment. These strain-specific requirements highlight the importance of tailoring pretreatment conditions to specific feedstocks. Structural, chemical, and morphological analyses demonstrated that microbial pretreatment reduced the amorphous lignin, increasing cellulose crystallinity and accessibility. These findings underscore the potential of microbial pretreatment to enhance biofuel production by modifying the lignocellulosic biomass. Such environmentally friendly bioconversion processes offer sustainable and cleaner energy solutions. Further research to optimize these methods for scalability and broader application is necessary in the pursuit for more efficient and greener biofuel production.

Insights into structure and activity of a UDP-GlcNAc 2-epimerase involved in secondary cell wall polymer biosynthesis in Paenibacillus alvei.

S-layer anchoring in Paenibacillus alvei is enabled by a non-covalent interaction between an S-layer homology domain trimer and a secondary cell wall polymer (SCWP), ensuring the structural integrity of the bacterial cell wall. Within the SCWP repeat, pyruvylated ManNAc serves as the ligand and the UDP-GlcNAc-2-epimerase MnaA supplies UDP-ManNAc to SCWP biosynthesis. To better understand SCWP biosynthesis and identify strategies for inhibiting pathogens with comparable cell wall architecture, like Bacillus anthracis, MnaA and rational variants were produced in E. coli and their kinetic constants determined. The effect of UDP-GlcNAc as a predicted allosteric activator and tunicamycin as a potential inhibitor of MnaA was tested in vitro supported by molecular docking experiments. Additionally, wild-type MnaA was crystallized. We present the crystal structure of unliganded P. alvei MnaA resolved at 2.20 Å. It adopts a GT-B fold consistent with other bacterial non-hydrolyzing UDP-GlcNAc 2-epimerases. A comparison of amino acid sequences reveals conservation of putative and known catalytic and allosteric-site residues in MnaA, which was confirmed through analysis of Q42A, Q69A, E135A and H241A MnaA variants. The kinetic parameters K M and k cat of MnaA were determined to be 3.91 mM and 33.44 s-1 for the forward, and 2.41 mM and 6.02 s-1 for the reverse reaction. While allosteric regulation by UDP-GlcNAc has been proposed as a mechanism for enzyme activation, UDP-GlcNAc was not found to be essential for UDP-ManNAc epimerization by P. alvei MnaA. However, the reaction rate doubled upon addition of 5% UDP-GlcNAc. Unexpectedly, the UDP-GlcNAc analog tunicamycin did not inhibit MnaA. Molecular docking experiments comparing tunicamycin binding of P. alvei MnaA and Staphylococcus aureus MnaA, which is inhibited by tunicamycin, revealed different residues exposed to the antibiotic excluding, those at the predicted allosteric site of P. alvei MnaA, corroborating tunicamycin resistance. The unliganded crystal structure of P. alvei MnaA reveals an open conformation characterized by an accessible cleft between the N- and C-terminal domains. Despite the conservation of residues involved in binding the allosteric activator UDP-GlcNAc, the enzyme is not strictly regulated by the substrate. Unlike S. aureus MnaA, the activity of P. alvei MnaA remains unaffected by tunicamycin.

Potential of Bacillus toyonensis and Paenibacillus alvei as Plant Growth Promoter on Melon Manis Terengganu (MMT)

Cucumis melo var inodorus cv. Manis Terengganu is known as Terengganu’s iconic fruits. However, MMT production is still insufficient to satisfy local demand. Over-reliance on chemical fertilizers to MMT has reduced soil fertility, degraded soil quality resistance, and negatively affected the environment. As a result, efficient microorganisms such as Paenibacillus alvei and Bacillus toyonensis were investigated as possible ecologically compatible biofertilisers for MMT. In this study, B. toyonensis and P. alvei produced indole-3-acetic acid (IAA) at concentrations of 20.49 µg.mL-1 and 19.18 µg.mL-1, respectively. hen, the greenhouse testing was conducted to evaluate the potentiality of effective microbes as plant growth promoter rhizobacteria by introducing the soil with B. toyonensis, P. alvei, and consortium. The experiment was laid out in a randomized complete block design (RCBD) with three groups of bacteria plus the control and each treatment replicated 15 times. Data were analyzed according to ANOVA procedure. As a result, B. toyonensis, P. alvei, and consortium significantly increased in all experimental growth parameters such as plant height, leaves, chlorophyll content, root mass, root length, leaf area, fruit weight, macronutrients, and micronutrients compared to control. Overall, the results showed that the effective single microbial strains promoted the development of MMT more effectively than the consortium

Structure Prediction and Genome Mining-Aided Discovery of the Bacterial C-Terminal Tryptophan Prenyltransferase PalQ.

Post-translational prenylations, found in eukaryotic primary metabolites and bacterial secondary metabolites, play crucial roles in biomolecular interactions. Employing genome mining methods combined with AlphaFold2-based predictions of protein interactions, PalQ , a prenyltransferase responsible for the tryptophan prenylation of RiPPs produced by Paenibacillus alvei, is identified. PalQ differs from cyanobactin prenyltransferases because of its evolutionary relationship to isoprene synthases, which enables PalQ to transfer extended prenyl chains to the indole C3position. This prenylation introduces structural diversity to the tryptophan side chain and also leads to conformational dynamics in the peptide backbone, attributed to the cis/trans isomerization that arises from the formation of a pyrrolidine ring. Additionally, PalQ exhibited pronounced positional selectivity for the C-terminal tryptophan. Such enzymatic characteristics offer a toolkit for peptide therapeutic lipidation.

Degradation of marine crustacean shell wastes through single-stage co-fermentation using proteolytic and chitinolytic bacteria.

Management of crustacean shell waste (SW) through an eco-friendly technique is an environmental obligation to control pollution. The present study showed a novel approach through the simultaneous application of proteolytic and chitinolytic bacteria to effectively degrade unprocessed crustacean SW. For this, the bacteria with concurrent chitinolytic and proteolytic activity (Bacillus subtilis, Priestia megaterium, or Bacillus amyloliquefaciens) were applied either alone or in combination with one proteolytic strain (Paenibacillus alvei) in the unprocessed lobster, crab, and shrimp SW. The method degraded the shells with high deproteinization (> 90%) and demineralization efficiency (> 90%). The degradation was confirmed through scanning electron microscopy. The highest weight loss achieved with shrimp, crab, and lobster shells was 93.67%, 82.60%, and 83.33%, respectively. B. amyloliquefaciens + P. alvei combination produced the highest weight loss in crab and lobster SW, whereas all combinations produced statistically similar weight loss in shrimp SW. There was a concurrent production of N-acetyl glucosamine (up to 532.89, 627.87, and 498.95 mg/g of shrimp, lobster, and crab shell, respectively, with P. megaterium + P. alvei and B. amyloliquefaciens + P. alvei in all SW) and amino acids (4553.8, 648.89, 957.27 μg/g of shrimp, lobster, and crab shells, respectively with B. subtilis + P. alvei in shrimp and B. amyloliquefaciens + P. alvei in crab and lobster). Therefore, it is concluded that, for the first time, efficient degradation of crustacean shell waste was observed using chitinolytic and proteolytic bacterial fermentation with the obtention of byproducts, providing a basis for further application in SW management.

Culturable Diversity and Biological Properties of Bacterial Endophytes Associated with the Medicinal Plants of Vernonia anthelmintica (L.) Willd

As one of the important traditional medicinal plants listed in the Chinese pharmacopoeia, Vernonia anthelmintica (L.) Willd has been shown to possess various biological activities. In this study, we characterized culturable endophytic bacteria associated with the medicinal plant V. anthelmintica collected from Hotan within the Xinjiang autonomous region of China. Bacterial endophytes were identified via 16S rRNA gene sequence analysis and compared to similar sequences from the GenBank. Isolated strains exhibited 99.08–100% similarity to Bacillus haynesii XJB-5, Bacillus proteolyticus XJB-16, Bacillus halotolerans XJB-35, Bacillus safensis XJB-71, Pseudomonas punonensis XJB-7, Lysinibacillus fusiformis XJB-17, Streptococcus lutetiensis XJB-66, Leclercia adecarboxylata XJB-12, Paenibacillus alvei XJB-14, and Pantoea agglomerans XJB-62. The ethyl acetate extracts of the bacterial endophytes demonstrated various pharmacological properties, such as antimicrobial, cytotoxic, antidiabetic, and antioxidant activity, according to a melanin content assay and have shown tyrosinase activity in murine B16 cells. A crude extract of B. halotolerans XJB-35 displayed more powerful biological activities than other bacterial endophytes; therefore, this strain was studied further in order to select the optimized parameters for enhancing the synthesis of bioactive compounds. The optimal culture medium was found to be nutrient broth (NB) medium, using peptone as its carbon source and yeast extract as its nitrogen source. A 24 h incubation time produced the optimal conditions for the maximum growth of B. halotolerans XJB-35 and the production of bioactive compounds. Moreover, we investigated the volatile chemical component of the dichloromethane fraction using GC-MS analysis. Our findings provide valuable information regarding the synthesize of bioactive natural products by B. halotolerans XJB-35 for use by the medicinal and pharmaceutical industries.

Molecular modelling and site-directed mutagenesis provide insight into saccharide pyruvylation by the Paenibacillus alvei CsaB enzyme

Pyruvylation is a biologically versatile but mechanistically unexplored saccharide modification. 4,6-Ketal pyruvylated N-acetylmannosamine within bacterial secondary cell wall polymers serves as a cell wall anchoring epitope for proteins possessing a terminal S-layer homology domain trimer. The pyruvyltransferase CsaB from Paenibacillus alvei served as a model to investigate the structural basis of the pyruvyltransfer reaction by a combination of molecular modelling and site-directed mutagenesis together with an enzyme assay using phosphoenolpyruvate (PEP; donor) and synthetic β-D-ManNAc-(1 → 4)-α-D-GlcNAc-diphosphoryl-11-phenoxyundecyl (acceptor). CsaB protein structure modelling was done using Phyre2 and I-Tasser based on the partial crystal structure of the Schizosaccharomyces pombe pyruvyltransferase Pvg1p and by AlphaFold. The models informed the construction of twelve CsaB mutants targeted at plausible PEP and acceptor binding sites and KM and kcat values were determined to evaluate the mutants, indicating the importance of a loop region for catalysis. R148, H308 and K328 were found to be critical to PEP binding and insight into acceptor binding was obtained from an analysis of Y14 and F16 mutants, confirming the modelled binding sites and interactions predicted using Molecular Operating Environment. These data lay the basis for future mechanistic studies of saccharide pyruvylation as a novel target for interference with bacterial cell wall assembly.

Extracts of Talaromyces purpureogenus Strains from Apis mellifera Bee Bread Inhibit the Growth of Paenibacillus spp. In Vitro.

Honey bees coexist with fungi that colonize hive surfaces and pollen. Some of these fungi are opportunistic pathogens, but many are beneficial species that produce antimicrobial compounds for pollen conservation and the regulation of pathogen populations. In this study, we tested the in vitro antimicrobial activity of Talaromyces purpureogenus strains isolated from bee bread against Paenibacillus alvei (associated with European foulbrood disease) and three Aspergillus species that cause stonebrood disease. We found that methanol extracts of T. purpureogenus strains B18 and B195 inhibited the growth of P. alvei at a concentration of 0.39 mg/mL. Bioactivity-guided dereplication revealed that the activity of the crude extracts correlated with the presence of diketopiperazines, a siderophore, and three unknown compounds. We propose that non-pathogenic fungi such as Talaromyces spp. and their metabolites in bee bread could be an important requirement to prevent disease. Agricultural practices involving the use of fungicides can disrupt the fungal community and thus negatively affect the health of bee colonies.

Inhibitive and prophylactic efficacy of lactic acid bacteria from Apis mellifera (Hymenoptera: Apidae) in combating Paenibacillus infections

Given the increasing interest in alternative methods of prevention and biological control of bacterial diseases in honey bees, the development of new approaches based on probiotic bacteria for honey bee growth, immune function and defense is important. Honey bees have a rich microbiota that varies with seasonal and geographic changes, developmental stages, diet, and social lifestyle. Nevertheless, lactic acid bacteria are an integral part of the honey bee microbiota. In this study, strains of Apilactobacillus, Leuconostoc and Enterococcus isolated from healthy honey bees were identified and their usefulness as an alternative product to control and prevent American and European foulbrood was investigated. The strains were identified by cultural and molecular analysis. The antimicrobial activities against Paenibacillus larvae and Paenibacillus alvei were tested by agar plug and well diffusion method. The inhibitory effect of the obtained 72-h cell-free supernatants on Paenibacillus larvae spore germination was determined by the Bioscreen C method. It turned out that the strains whose prophylactic effect against Paenibacillus larvae spores in larvae was tested were not largely able to prevent infection. Apilactobacillus and Leuconostoc strains did not affect the health of the larvae, and infection was somewhat clinically eliminated in larvae colonized by Apilactobacillus and Enterococcus. The fact that the strains exhibit potent antimicrobial activity and do not reduce larval viability and live weight is a promising finding with regard to their use for treatment, particularly in the early stages of American foulbrood infection.

Identification and Evaluation of the Growth Promotion of Endophytic Bacteria on in vitro Potato Plants.

<b>Background and Objective:</b> Isolation and investigation of plant growth promoting bacteria on potato plants can provide significant information for the application of beneficial bacteria in potato production. This study aims to isolate and characterize endophytic bacteria isolated from potato roots. In addition, the potential application of endophytes in promoting potato growth under <i>in vitro</i> conditions was also investigated. <b>Materials and Methods:</b> The roots from 15 healthy potato plants were excised and surface sterilized by NaOCl and finally rinsed by sterilized water. The confirmed surface-sterilized roots were then aseptically cut into small fragments and spread onto the isolation media, followed by incubation at 27°C for up to 3 days. Six isolates that showed differences in colony morphology were selected for further investigation. All isolates were screened for IAA production, nitrogen fixation, and phosphate solubilization. <b>Results:</b> Five of the isolates were identified as <i>Bacillus</i> and isolate 30 was identified as <i>Paenibacillus alvei</i>. All isolates exhibited good IAA production. While Iso-27 had no nitrogen fixation activity, Iso-28 showed the highest level of nitrogen fixation activity (3.59 mg L<sup>1</sup>), four isolates (Iso-9, Iso-10, Iso-11, Iso-28) could solubilize phosphate, ranging from 49.64 g L<sup>1</sup> to 67.98 mg L<sup>1</sup>. After being inoculated with <i>in vitro</i> potato plants, isolates 9, 10, 28, 30, improved the stalk length, root number, fresh mass and dried mass of the potato plants. <b>Conclusion:</b> The four isolates can potentially be applied in <i>in vitro</i> potato culture.

Phosphate solubilizing bacteria inducing systemic resistance with a potential for use as biofertilizer for rice

Induced systemic resistance (ISR) and biofertilizer are two activities in plant protection from pathogens as well as an alternative to the use of traditional fertilizers. The purpose of the study was to determine other features of 4 bacteria that have the ability as phosphate solvents and produce indole and siderophore compounds that determine them as inducers of systemic resistance and indicate their possibility to be applied as biofertilizers in rice plants. This study is experimental with four (4) bacteria that have been identified and characterized molecularly: Paenibacillus alvei AP4SR, Paenibacillus alvei AP6SR, Bacillus cereus RH8SR, and Bacillus cereus RH10SR. The results showed that the characteristics of the four bacteria could be applied as biofertilizers. The ability to fix nitrogen was shown by Paenibacillus alvei AP4SR, Paenibacillus alvei AP6SR and Bacillus cereus RH10SR, while the ability to dissolve potassium was shown by Paenibacillus alvei AP4SR, Bacillus cereus RH8SR, and Bacillus cereus RH10SR. Only three isolates were able to increase plant metabolite levels, namely Paenibacillus alvei AP4SR, Bacillus cereus RH10SR and Bacillus cereus RH8SR. Bacterial inoculation had a significant effect on plant height and the number of tillers at the age of 40 days, the number of tillers/plant increased to 56.52%..

ISOLATION AND CHARACTERIZATION OF CELLULOSE-DEGRADING BACTERIA FROM DECOMPOSING PLANT MATTER

Objective: The green plant waste consists of a high amount of lignocellulosic materials offering an intense environment for the growth of cellulolytic bacteria, which have ability to degrade plant biomass as a carbon source. This cellulase produced can be used to break down plant waste into valuable products such as monomeric sugars, biofuels, compost etc. Therefore, the aim of present study was to isolate and identify potent cellulose-degrading bacteria from decomposing plant matter and assessment of their cellulolytic activity. Methods: The cellulolytic bacteria were isolated by serial dilution technique on CMC agar media and six isolates were selected based on their cellulose hydrolysing ability. Based on the biochemical tests such as Oxidase test, Voges-Proskauer test, Methyl red test, Catalase test and sequence analysis of 16s rRNA genes. Results: The isolates were identified as Paenibacillus alvei, Paenibacillus lentimorbus, Bacillus subtilis, Bacillus nakamurai with percentage identity of 93.77%, 92.80%, 97.71% and 91.94%, respectively, as obtained from NCBI BLAST. Among these Paenibacillus alvei showed the highest cellulase activity. Conclusion: The findings of this study could pave the way for the use of cellulose as an inexpensive energy source for bacteria that are capable of producing valuable products.

Dark fermentation of pretreated hydrolysates of pineapple fruit waste for the production of biohydrogen using bacteria isolated from wastewater sources

ABSTRACT In the present study, both acidic and alkaline hydrolysate of pineapple waste was utilised for the production of biohydrogen using locally isolated bacterial strains. The bacteria were isolated from different wastewater sources and were identified as Proteus mirabilis, Pseudomonas aeruginosa, Bacillus altitudinus, Bacillus subtilis, Paenibacillus alvei, and Lysinibacillus sphaericus. Experimental results showed that the highest biohydrogen yield of 836.33 ± 48.02 mL H2 was produced from alkaline hydrolysate with Bacillus altitudinis during the 96thhr of fermentation. Among the different bacterial strains, B. altitudinis showed higher H2 production. Comparatively alkaline hydrolysates exhibited a higher yield of hydrogen than acidic hydrolysates. The final pH of the experiment was found to be in acidic range. The total VFA concentration ranged between 930 ± 207.85 mg/L to 3050 ± 476.97 mg/L. Both sugar degradation and COD reduction were more than 80% in the acidic and alkaline hydrolysates while the lowest sugar degradation and COD reduction were observed for the untreated biomass. The rationale behind this study was to convert the waste biomass into energy by utilising the potential of native bacterial communities.

Copper and iron metal resistant rhizospheric bacteria boost the plant growth and bacoside A content in Bacopa monnieri under stress conditions.

Bacteria that enhance plant growth and development and are found in the vicinity of roots are referred to as plant growth-promoting rhizobacteria. Some beneficial bacteria help plant tolerance to many hazardous chemical elements. In this context, Cupriavidus basilensis, Novosphingobium humi, Bacillus zanthoxyli, Bacillus sp., Paenibacillus alvei, Ancylobacter aquaticus and Ralstonia syzygii metal-tolerant rhizospheric bacteria were isolated from rhizospheric soil associated with Bacopa monnieri. The beneficial effects of rhizospheric bacteria on B. monnieri plant physiology and biochemical responses were investigated under pot conditions at two levels (100μM and 500μM) of CuSO4 or FeCl3. N. humi, A. aquaticus and R. syzygii bacterial strains were associated with significantly increased height and biomass under normal and stress conditions. An assay for indole acetic acid in isolated rhizospheric bacteria found differential secretion except Bacillus zanthoxyli. Bacoside A is a major phytocompound in B. monnieri with medicinal value; maximum induction was observed in the R. syzygii treatment. High concentration of copper and iron salts negatively influenced height, biomass and photosynthetic pigments; however N. humi, A. aquaticus, Bacilllus sp. and R. syzygii beneficial bacterial helped plants under stress conditions. Moreover, a significant enhancement in chlorophyll a and b was noticed in C. basilensis, B. zanthoxyli, Bacilllus sp., P. alvei and R. syzygii treatments, without much influence on carotenoid levels. Therefore, the present study emphasises the importance of isolating plant growth-promoting rhizobacteria for use in bacopa plants exposed to metals such as copper and iron in soil.

In the battle of the disease: a transcriptomic analysis of European foulbrood-diseased larvae of the Western honey bee (Apis mellifera)

BackgroundEuropean foulbrood is a significant bacterial brood disease of Apis sp. and can cause severe and devastating damages in beekeeping operations. Nevertheless, the epidemiology of its causative agent Melissococcus plutonius has been begun to uncover but the underlying mechanisms of infection and cause of disease still is not well understood. Here, we sought to provide insight into the infection mechanism of EFB employing RNAseq in in vitro reared Apis mellifera larvae of two developmental stages to trace transcriptional changes in the course of the disease, including Paenibacillus alvei secondary infected individuals.ResultsIn consideration of the progressing development of the larva, we show that infected individuals incur a shift in metabolic and structural protein-encoding genes, which are involved in metabolism of crucial compounds including all branches of macronutrient metabolism, transport protein genes and most strikingly chitin and cuticle associated genes. These changes underpin the frequently observed developmental retardation in EFB disease. Further, sets of expressed genes markedly differ in different stages of infection with almost no overlap. In an earlier stage of infection, a group of regulators of the melanization response cascade and complement component-like genes, predominantly C-type lectin genes, are up-regulated while a differential expression of immune effector genes is completely missing. In contrast, late-stage infected larvae up-regulated the expression of antimicrobial peptides, lysozymes and prominent bacteria-binding haemocyte receptor genes compared to controls. While we clearly show a significant effect of infection on expressed genes, these changes may partly result from a shift in expression timing due to developmental alterations of infection. A secondary infection with P. alvei elicits a specific response with most of the M. plutonius associated differential immune effector gene expression missing and several immune pathway genes even down-regulated.ConclusionWe conclude that with progressing infection diseased individuals undergo a systemic response with a change of metabolism and their activated immune defence repertoire. Moreover, larvae are capable of adjusting their response to a secondary invasion in late stage infections.

Identification of Distinct Endosymbionts of Whiteflies-infesting Cassava (Manihot esculenta Crantz), using Diagnostic PCR and Sanger Sequencing

The study was conducted during March–December 2021 in Thiruvananthapuram, Kerala for the identification of distinct endosymbionts of cassava whiteflies (Bemisia tabaci (Gennadius) and Aleurodicus dispersus (Russell). Endosymbiotic bacteria found in whiteflies have been reported to interact and provide specific advantages to the hosts and they can be one of the reasons for whiteflies’ insecticidal resistance. In the present study, endosymbiotic bacteria were isolated from the insects, allowed to grow in media after insecticidal treatments and after observing colony morphology, distinct bacterial colonies were sub-cultured and selected for further molecular identification procedures. PCR analysis was carried out for bacteria using 16S rRNA primer, with an annealing temperature of 49°C and yielded fragments at 1500 bp. Based on the sequencing report the observations were that the culturable endosymbionts Providencia present in B. tabaci is resistant to chlorpyrifos and Paenibacillus alvei present in A. dispersus is resistant to imidacloprid and chlorpyrifos. Clostridium senegalens and Acinetobacter are found in control populations of Bemisia and Aleurodicus respectively.The sequences were submitted to NCBI and the accession numbers obtained were OP303253, OP303256, OP303254 and OP295124. Also, through diagnostic PCR using specific bacterial primers, presence of Portiera aleyrodidarum at fragment length of 1000 bp and Wolbachia at 650 bp in B. tabaci and Rickettsia at fragment length of 800 bp in A. dispersus are confirmed. The study could identify bacteria which are decisive in their presence and activity in whiteflies.

Screening of indole-3-acetic acid PGPB from three agricultural systems at Nakhon Pathom, Thailand

Abstract. Homthong M, Kaewpuk W, Yamsuan S, Thongsima A, Mokkapan K, Pikulthong V. 2022. Screening of indole-3-acetic acid PGPB from three agricultural systems at Nakhon Pathom, Thailand. Biodiversitas 23: 5935-5941. Plant growth-promoting bacteria (PGPB) are associated with plant roots and enhance growth via a variety of mechanisms, including fixation of atmospheric nitrogen, solubilization of phosphorus, phytohormone synthesis, and plant phenolic compound stimulation. Sixty-five isolated bacteria from the three agricultural systems in Nakhon Pathom were screened for IAA production. The results showed that seven isolates—C01-28, C02-48, C02-51, G01-34, G03-25, G03-38, and O02-46—produced IAA under L-tryptophan as a precursor at values of 9.08 ± 0.51, 68.64 ± 29.07, 40.67 ± 18.04, 10.65 ± 1.07, 63.30 ± 1.15, 37.73 ± 1.80, and 121.28 ± 15.20 mg mL-1, respectively. Capability on plant growth-promoting traits revealed that none of the isolates stimulated ten-morning glory (Ipomoea aquatica Forsk.) seedling growth, which was not significantly different from the control. Isolates O02-46 enhanced salicylic acid (SA) in ten-morning glory seedlings the most, showing 7.18 ± 1.78 µg g-1 of fresh weight, while isolates G01-34 enhanced phenolic compound (PC) production the most showing 218.18 ± 29.55 mg GAE g-1 extract, respectively. The 16S rRNA analysis revealed that isolates O02-46, C02-48, G03-25, and C02-51 were identified as similar to Paenibacillus alvei at 99.20% (Accession number AY826588.1), Bacillus megaterium at 79.91% (Accession number MH031358.1), Bacillus sp. at 98.57% (Accession number JF322976.1), and Lysinibacillus fusiformis at 99.61% (Accession number HE610782.1).