A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N′-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 °C. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.
Verticillium dahliae (Vd) is a soil-borne vascular pathogen which causes severe wilt symptoms in a wide range of plants. The microsclerotia produced by the pathogen survive in soil for more than 15 years. Here we demonstrate that an exudate preparation induces cytoplasmic calcium elevation in Arabidopsis roots, and the disease development requires the ethylene-activated transcription factor EIN3. Furthermore, the beneficial endophytic fungus Piriformospora indica (Pi) significantly reduced Vd-mediated disease development in Arabidopsis. Pi inhibited the growth of Vd in a dual culture on PDA agar plates and pretreatment of Arabidopsis roots with Pi protected plants from Vd infection. The Pi-pretreated plants grew better after Vd infection and the production of Vd microsclerotia was dramatically reduced, all without activating stress hormones and defense genes in the host. We conclude that Pi is an efficient biocontrol agent that protects Arabidopsis from Vd infection. Our data demonstrate that Vd growth is restricted in the presence of Pi and the additional signals from Pi must participate in the regulation of the immune response against Vd.
Many studies have been now focused on the promising approach of fungal endophytes to protect the plant from nutrient deficiency and environmental stresses along with better development and productivity. Quantitative and qualitative protein characteristics are regulated at genomic, transcriptomic, and posttranscriptional levels. Here, we used integrated in-depth proteome analyses to characterize the relationship between endophyte Piriformospora indica and Brassica napus plant highlighting its potential involvement in symbiosis and overall growth and development of the plant. An LC-MS/MS based label-free quantitative technique was used to evaluate the differential proteomics under P. indica treatment vs. control plants. In this study, 8,123 proteins were assessed, of which 46 showed significant abundance (34 downregulated and 12 upregulated) under high confidence conditions (p-value ≤ 0.05, fold change ≥2, confidence level 95%). Mapping of identified differentially expressed proteins with bioinformatics tools such as GO and KEGG pathway analysis showed significant enrichment of gene sets involves in metabolic processes, symbiotic signaling, stress/defense responses, energy production, nutrient acquisition, biosynthesis of essential metabolites. These proteins are responsible for root’s architectural modification, cell remodeling, and cellular homeostasis during the symbiotic growth phase of plant’s life. We tried to enhance our knowledge that how the biological pathways modulate during symbiosis?