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Sheath rot of rice is one of the most devastating diseases of rice due to its ability to reduce the yield significantly in all rice cultivating areas of India. The purpose of this study was to assess the effectiveness of Bacillus cereus strain RBS-57 against sheath rot disease of rice. In addition, it enables us to understand the molecular mechanism of the host–pathogen-bioagent interactions using a proteomic approach. A combination of seed treatment, seedling dip, and foliar spray with RBS-57 liquid formulation has recorded the lowest sheath rot disease index, both under pot experiment (21.33%) and field conditions (15.33% in trial I and 12.42% in trial II, respectively). In addition to that, RBS-57 application enhanced the plant growth and yield attributes. Moreover, a 2D-PAGE study uses protein profiling to illustrate the molecular response of the tripartite interaction between host–pathogen-bioagent. MALDI-TOF mass spectrometry (MS/MS) analysis identified a total of 20 differentially expressed proteins, primarily implicated in plant metabolism and development, defense response, transcription and signalling. Selected genes were validated by quantitative Real-Time PCR (qRT-PCR) analysis. The alterations in protein abundance and transcripts were positively correlated for all the genes. The present study provides initial insights into the molecular mechanism that underlies the tripartite interaction between the host–pathogen-bioagent in rice plants. [ABSTRACT FROM AUTHOR]

The application of lactic acid bacteria (LAB) can be a challenging yet promising tool to control the endogenous microbiota during malting and to improve malt quality. In this study, a food-grade malt-based ingredient was fermented using an antifungal strain, Lactobacillus brevis R2Δ, and applied on barley grains during steeping and germination. Different variations of starter culture concentration and cell-free supernatant were compared to a control solution during pilot-scale malting trials. All treated barley samples showed a significant decrease in aerobic bacteria (up to 99.8% reduction) and a promotion of yeast growth when compared to the untreated control. The number of kernels contaminated with Fusarium spp. could be reduced by more than 90%, as confirmed by qPCR analysis. Shorter rootlets coincided with lower malting losses (−31.8%) and with increased extract yield (+3.1%). Differences in the enzymatic activity between the malts did not significantly alter the processability of the malts during brewhouse operations. Throughout yeast fermentation, no negative impact of LAB could be detected for the majority of attributes tested. Overall, the treatment containing living starter cultures and the highest amount of total titratable acidity (71 mmol L) showed the most promising results when aimed at further enhancing the quality and safety of barley malt. [ABSTRACT FROM AUTHOR]

We develop a comprehensive biogeochemical framework for understanding and quantitatively evaluating metals bio-protection in sulfidic microbial systems. We implement the biogeochemical framework in CCBATCH by expanding its chemical equilibrium and biological sub-models for surface complexation and the formation of soluble and solid products, respectively. We apply the expanded CCBATCH to understand the relative importance of the various key ligands of sulfidic systems in Zn detoxification. Our biogeochemical analysis emphasizes the relative importance of sulfide over other microbial products in Zn detoxification, because the sulfide yield is an order of magnitude higher than that of other microbial products, while its reactivity toward metals also is highest. In particular, metal-titration simulations using the expanded CCBATCH in a batch mode illustrate how sulfide detoxifies Zn, controlling its speciation as long as total sulfide is greater than added Zn. Only in the absence of sulfide does complexation of Zn to biogenic organic ligands play a role in detoxification. Our biogeochemical analysis conveys fundamental insight on the potential of the key ligands of sulfidic systems to effect Zn detoxification. Sulfide stands out for its reactivity and prevalence in sulfidic systems. [ABSTRACT FROM AUTHOR]