Metagenomic profiling of tomato rhizosphere delineates the diverse nature of uncultured microbes as influenced by Bacillus velezensis VB7 and Trichoderma koningiopsis TK towards the suppression of root-knot nematode under field conditions.

The plant-parasitic Root Knot Nematodes (Meloidogyne spp.,) play a pivotal role to devastate vegetable crops across the globe. Considering the significance of plant-microbe interaction in the suppression of Root Knot Nematode, we investigated the diversity of microbiome associated with bioagents-treated and nematode-infected rhizosphere soil samples through metagenomics approach. The wide variety of organisms spread across different ecosystems showed the highest average abundance within each taxonomic level. In the rhizosphere, Proteobacteria, Firmicutes, and Actinobacteria were the dominant bacterial taxa, while Ascomycota, Basidiomycota, and Mucoromycota were prevalent among the fungal taxa. Regardless of the specific treatments, bacterial genera like Bacillus, Sphingomonas, and Pseudomonas were consistently found in high abundance. Shannon diversity index vividly ensured that, bacterial communities were maximum in B. velezensis VB7-treated soil (1.4-2.4), followed by Root Knot Nematode-associated soils (1.3-2.2), whereas richness was higher with Trichoderma konigiopsis TK drenched soils (1.3-2.0). The predominant occurrence of fungal genera such as Aspergillus Epicoccum, Choanephora, Alternaria and Thanatephorus habituate rhizosphere soils. Shannon index expressed the abundant richness of fungal species in treated samples (1.04-0.90). Further, refraction and species diversity curve also depicted a significant increase with maximum diversity of fungal species in B. velezensis VB7-treated soil than T. koningiopsis and nematode-infested soil. In field trial, bioagents-treated tomato plant (60% reduction of Meloidogyne incognita infection) had reduced gall index along with enhanced plant growth and increased fruit yield in comparison with the untreated plant. Hence, B. velezensis VB7 and T. koingiopsis can be well explored as an antinemic bioagents against RKN. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03851-1.

Bioconversion of industrial solid waste--cassava bagasse for pullulan production in solid state fermentation.

The purpose of the work was to produce commercially important pullulan using industrial solid waste namely cassava bagasse in solid state fermentation and minimize the solid waste disposal problem. First, influence of initial pH on cell morphology and pullulan yield was studied. Effect of various factors like fermentation time, moisture ratio, nitrogen sources and particle size on pullulan yield was investigated. Various supplementary carbon sources (3%, w/w) namely glucose, sucrose, fructose, maltose, mannose and xylose with cassava bagasse was also studied to improve the pullulan yield. After screening the suitable supplement, effect of supplement concentration on pullulan production was investigated. The pullulan from cassava bagasse was characterized by FTIR, (1)H-NMR and (13)C-NMR. Molecular weight of pullulan from cassava bagasse was determined by gel permeation chromatography. Thus, cassava bagasse emerged to be a cheap and novel substrate for pullulan production.

Dichlorido(dimethyl-glyoximato-κN,N')(dimethyl-glyoxime-κN,N')cobalt(III).

In the title compound, [Co(C(4)H(7)N(2)O(2))Cl(2)(C(4)H(8)N(2)O(2))], the Co(III) ion has a distorted octa-hedral coordination environment. The equatorial plane consists of four N atoms, two each from the dimethyl-glyoxime and dimethyl-glyoximate ligands, while the two axial positions are occupied by two chloride ions. Strong intra-molecular O-H⋯O hydrogen bonds are observed between the dimethyl-glyoxime and dimethyl-glyoximate ligands. Mol-ecules are linked into a chain running along the [101] direction by O-H⋯O and C-H⋯Cl hydrogen bonds. The chains are cross-linked through inter-molecular C-H⋯Cl hydrogen bonds.