cellulase and tricalcium-phosphate

Plant growth promoting rhizobacteria (PGPR) are studied in different agricultural crops but the interaction of PGPR of tea crop is not yet studied well. In the present study, the indigenous tea rhizobacteria were isolated from seven tea estates of Darjeeling located in West Bengal, India. A total of 150 rhizobacterial isolates were screened for antagonistic activity against six different fungal pathogens i.e. Nigrospora sphaerica (KJ767520), Pestalotiopsis theae (ITCC 6599), Curvularia eragostidis (ITCC 6429), Glomerella cingulata (MTCC 2033), Rhizoctonia Solani (MTCC 4633) and Fusarium oxysporum (MTCC 284), out of which 48 isolates were antagonist to at least one fungal pathogen used. These 48 isolates exhibited multifarious antifungal properties like the production of siderophore, chitinase, protease and cellulase and also plant growth promoting (PGP) traits like IAA production, phosphate solubilization, ammonia and ACC deaminase production. Amplified ribosomal DNA restriction analysis (ARDRA) and BOX-PCR analysis based genotyping clustered the isolates into different groups. Finally, four isolates were selected for plant growth promotion study in two tea commercial cultivars TV-1 and Teenali-17 in nursery conditions. The plant growth promotion study showed that the inoculation of consortia of these four PGPR isolates significantly increased the growth of tea plant in nursery conditions. Thus this study underlines the commercial potential of these selected PGPR isolates for sustainable tea cultivation.

Topics: Alphaproteobacteria; Ammonia; Antifungal Agents; Bacterial Proteins; Calcium Phosphates; Camellia sinensis; Carbon-Carbon Lyases; Cellulase; Chitinases; DNA, Fungal; Fungi; Genotype; Glycoside Hydrolases; India; Indoleacetic Acids; Phylogeny; Plant Roots; RNA, Ribosomal, 16S; Siderophores; Soil Microbiology

Fungal mycelia mass and pigments are major obstacles to investigating the secretion of bioactive substances such as enzyme activities using a plate assay. In this study, we applied a cellophane membrane and demonstrated that it can block mycelia mass and conidia (especially pigmented spores that would likely interfere with any subsequent color development-based activity detection) while allowing secreting enzymes to pass through. Visual observation after lifting the cellophane membrane and the collected mycelia and conidia indicated that the bioactivities on specific plates were improved significantly, although some fungal growth hurdle was noted. This proved to be true whether the assays were color development based or not.

Topics: Calcium Phosphates; Cellophane; Cellulase; Mycelium; Spores, Fungal; Trichoderma