Multifarious Indigenous Diazotrophic Rhizobacteria of Rice (Oryza sativa L.) Rhizosphere and Their Effect on Plant Growth Promotion

A diverse group of rhizobacteria persists in the rhizospheric soil, on the surface of roots, or in association with rice plants. These bacteria colonize plant root systems, enhance plant growth and crop yield. Indigenous rhizobacteria are known to promote soil health, grain production quality and serve as sustainable bioinoculant. The present study was aimed to isolate, identify and characterize indigenous plant growth promoting (PGP) diazotrophic bacteria associated with the rhizosphere of rice fields from different areas of Jammu and Kashmir, India. A total of 15 bacteria were isolated and evaluated for various PGP traits, antagonistic activity against phytopathogens, production of hydrolytic enzymes and biofilm formation under in-vitro conditions. The majority of the isolated bacteria were Gram-negative. Out of 15 bacterial isolates, nine isolates produced IAA (12.24 ± 2.86 to 250.3 ± 1.15 μg/ml), 6 isolates exhibited phosphate solubilization activity (36.69 ± 1.63 to 312.4 ± 1.15 μg/ml), 7 isolates exhibited rock phosphate solubilization while 5 isolates solubilized zinc (10–18 mm), 7 isolates showed siderophore production, 8 isolates exhibited HCN production, 6 isolates exhibited aminocyclopropane-1-carboxylate (ACC) deaminase activity, 13 isolates exhibited cellulase activity, nine isolates exhibited amylase and lipase activity and six isolates exhibited chitinase activity. In addition, 5 isolates showed amplification with the nifH gene and showed a significant amount of nitrogenase activity in a range of 0.127–4.39 μmol C2H4/mg protein/h. Five isolates viz., IHK-1, IHK-3, IHK-13, IHK-15 and IHK-25 exhibited most PGP attributes and successfully limited the mycelial growth of Rhizoctonia solani and Fusarium oxysporum in-vitro. All the five bacterial isolates were identified based on morphological, biochemical and 16S rDNA gene sequencing study, as Stenotrophomonas maltophilia, Enterobacter sp., Bacillus sp., Ochrobactrum haematophilum and Pseudomonas aeruginosa. Rice plants developed from seeds inoculated with these PGP strains individually had considerably higher germination percentage, seed vigor index and total dry biomass when compared to control. These findings strongly imply that the PGP diazotrophic bacteria identified in this work could be employed as plant growth stimulators in rice.

Biodegradation Potential of SteccherinumOchraceum: Growth on Different Wood Types and Preliminary Evaluation of Enzymatic Activities

White-rot fungi isa source of a great variety of oxidative and hydrolytic enzymes suitable for biotechnological applications, e.g. in pulp and paper, textile and food industries, bioethanol production, degradation of recalcitrant environmental pollutants,and others. Steccherinumochraceum is a xylotrophicwhite-rot basidiomycetethat can be found in variousclimatic zones on different woody substrates (mostly well decayed). For this research, seventeenstrains of S. ochraceumwere collected in different regions of Russia from various wood substrates (aspen, alder, oak, hazel, birch and willow). Phylogeneticanalyseswere performedbasedon the nucleotide sequences of ITS1, ITS2, 5.8S rRNA, 28S rRNA, β-tubulin and tef1.Oxidaseandcellulaseactivitieswereassessedbyplate-tests with ABTS and CMC. Forevaluation of biodegradation potential,solid state fermentation on alder and pine sawdust wasperformed. Weightanddensitylossaswellas the C:Nratioweremeasuredafter 90 days of cultivation.All S. ochraceum strains exhibited high oxidative activity towards ABTS, indicating secretion of oxidative enzymes (i.e. laccases and class II peroxidases). Cellulase activity was medium or low for most strains and in some strains – absent. Allstrainswereabletodegradealderandpinesawdust. There was no correlation between the enzymatic activity, biodegradation potential and geographic origin of S. ochraceum strains. However, S. ochraceum strains isolated from the same wood substrates exhibited similar characteristics in most cases. Strain LE-BIN 3398 was the most effective for degrading both alder and pine sawdust and could be regarded as a promising source of oxidative enzymes for biotechnology. Keywords: basidiomycetes, biodegradation, solid state fermentation, oxidase activity, Steccherinumochraceum

Differences of Enzymatic Activity During Composting and Vermicomposting of Sewage Sludge Mixed With Straw Pellets

The study aims were focused on profiling eight hydrolytic enzymes by fluorescence method using a multifunctional modular reader and studying the proportion of basic microorganism groups during composting and vermicomposting of sewage sludge mixed with straw pellets in several proportions (0, 25, 50, 75, and 100%). The greatest decrease in enzymatic activity occurred in the first half of composting and vermicomposting. After 4 months of these processes, the least enzymatic activity was observed in the sludge with 50% and also 25% straw addition, indicating that straw is an important means for the rapid production of mature compost from sewage sludge. Enzymatic activity was usually less in the presence of earthworms than in the control treatment because some processes took place in the digestive tract of the earthworm. For the same reason, we observed reduced enzyme activity during fresh feedstock vermicomposting than precomposted material. The final vermicompost from fresh feedstocks exhibited less microbial biomass, and few fungi and G− bacteria compared to precomposted feedstock. The enzymatic activity during composting and vermicomposting of sewage sludge and their mixtures stabilized at the following values: β-D-glucosidase—50 μmol MUFG/h/g dw, acid phosphatase—200 μmol MUFP/h/g dw, arylsulphatase—10 μmol MUFS/h/g dw, lipase—1,000 μmol MUFY/h/g dw, chitinase—50 μmol MUFN/h/g dw, cellobiohydrolase—20 μmol MUFC/h/g dw, alanine aminopeptidase—50 μmol AMCA/h/g dw, and leucine aminopeptidase—50 μmol AMCL/h/g dw. At these and lesser values, these final products can be considered mature and stable.

Hydrolytic enzymes in therapy of gestosis

The clinical effectiveness o f complex enzymotherapy with preparation Vobenzim in treatment o f gestosis was studied in comparison with traditional therapy. The author analyzes the course оf gestation and delivery, and the state оf neonates in women with nephropathy o f I degree, who got common treatment (28 patients) and complex treatment including Vobenzim (17patients). Positive clinical effect o f complex enzymotherapy in case o f nephropathy is displayed in decreasing of edematic syndrome, eliminating or decreasing o f proteinuria, lowering o f blood pressure and impairment o f fetalhypoxia in labors. It goes along with the reduction o f immune complexes fixed in placenta.

Enzyme profile in samples of bacterial cellulose film treated with Trametes versicolor and Coniophora puteana

Profile of enzymes in samples of bacterial cellulose film treated with Trametes versicolor and Coniophora puteana. The paper presents the results of research showing the profile of hydrolytic enzymes synthesized by fungi that cause decomposition of wood during growth on film samples made of bacterial cellulose. The performed analyzes allowed for the conclusion that the presence of cellulose in the culture medium stimulates the fungal cells to synthesize full groups of enzymes that are not produced on the agarmaltose medium. Among the synthesized enzymes, both species of fungi produced two enzymes: β - glucosidase and N-acetyl-β - glucuronidase with the highest observed activity.

Screening of halotolerant microfungi isolated from hypersaline soils of Algerian Sahara for production of hydrolytic enzymes

The Algerian Sahara contains numerous hypersaline ecosystems including salt lakes in which the fungal diversity has not been characterized. The abundance and diversity of soil microofungi in three salt lakes in southeastern Algeria was investigated together with their profiles of hydrolytic enzyme. Fungal population size and relative abundance were determined in about 75 soil samples by plate count. From 69 fungal isolates, 46.38% were Aspergillus, 20.29% were Penicillium and 11.59% belonging to Cladosporium genus. The sixty-nine isolates have been studied at different constant temperatures and salinities. All fungal isolates are halotolerant or halophiles with the ability to grow at 50°C. The screening for extracellular halophilic enzymes at 40°C showed that 69.57% of the isolates were able to produce at least two types of the screened enzymes. Protease was the most abundant enzyme detected in 60.87% of the total isolates. The results obtained of all the growth tests indicate the adaptability of fungal isolates tested to the extreme conditions and their possible utilisation as producers of halophilic-active hydrolytic enzymes.

Early Secretory Pathway-Associated Proteins SsEmp24 and SsErv25 Are Involved in Morphogenesis and Pathogenicity in a Filamentous Phytopathogenic Fungus

Understanding the reproduction and pathogenesis mechanism of phytopathogens could provide new opinions to effectively control fungal diseases. Although it has been known that effectors and extracellular hydrolytic enzymes secreted by phytopathogenic fungi play important roles in fungus-host interactions, the secretion system for the delivery of virulence factors to the host is still largely undescribed.