Project description:During second generation biofuel production, optimization of cellulase activity is vital for synthesizing the end-product of anaerobic fermentation, bio-ethanol. The slightest change in pH, temperature, dissolved oxygen, carbon utilization, and addition or removal of essential supplements can reduce the secretion of necessary enzymes to degrade cellulosic biomass; resulting in a loss of free glucose. Determining the ecological effects of certain key media components is essential to understand how the bacterial or fungal colony will respond to a fluid cellulolytic environment. For our experiment a custom cellulosic media was designed to enhance the industrially important and recently isolated thermophile, Bacillus licheniformis YNP5-TSU. After several attempts to simplify the carboxymethylcellulose (CMC) media composition, impaired biofilm maturation and parallel declined cellulase activity was noticed. This negative artifact occurred during flask fermentation only when magnesium sulfate was removed from broth media. To analyze the shift in enzymatic gene expression, biofilm associated proteins were extracted and quantified through TMT10plex mass tag isobaric labeling of both magnesium sufficient (4.0mM MgSO4) and magnesium depleted media after 24hrs and 48hrs incubation periods. Raw data generated from nanoLC-MS/MS using an Orbitrap Fusion mass spectrometer identified over 2,000 proteins from both control and magnesium depleted samples when searched against the whole genome sequence of Bacillus licheniformis YNP5-TSU (NCBI accession number MEDD00000000). After statistical normalization and false discovery rate were calculated, 140 upregulated/downregulated expressed proteins were shown with 2σ significance to be effected by magnesium concentrations. In a closer look through STRING protein co-expression webs, over 15 were directly related to biofilm and cellulase activity, with fold changes as high as 5.78. Through this proteomic study of Bacillus licheniformis YNP5-TSU we are able to provide significant evidence that; (1) biofilm maturation and cellulase production are highly correlated and (2), their optimization is dependent upon by the addition of magnesium, an essential mineral for growth.
Project description:Acetoin is a potential platform compound for a variety of chemicals. Bacillus licheniformis MW3, a thermophilic and generally regarded as safe (GRAS) microorganism, can produce 2,3-butanediol with a high concentration, yield, and productivity. In this study, B. licheniformis MW3 was metabolic engineered for acetoin production. After deleting two 2,3-butanediol dehydrogenases encoding genes budC and gdh, an engineered strain B. licheniformis MW3 (?budC?gdh) was constructed. Using fed-batch fermentation of B. licheniformis MW3 (?budC?gdh), 64.2 g/L acetoin was produced at a productivity of 2.378 g/[L h] and a yield of 0.412 g/g from 156 g/L glucose in 27 h. The fermentation process exhibited rather high productivity and yield of acetoin, indicating that B. licheniformis MW3 (?budC?gdh) might be a promising acetoin producer.
Project description:To resist to ?-lactam antibiotics Eubacteria either constitutively synthesize a ?-lactamase or a low affinity penicillin-binding protein target, or induce its synthesis in response to the presence of antibiotic outside the cell. In Bacillus licheniformis and Staphylococcus aureus, a membrane-bound penicillin receptor (BlaR/MecR) detects the presence of ?-lactam and launches a cytoplasmic signal leading to the inactivation of BlaI/MecI repressor, and the synthesis of a ?-lactamase or a low affinity target. We identified a dipeptide, resulting from the peptidoglycan turnover and present in bacterial cytoplasm, which is able to directly bind to the BlaI/MecI repressor and to destabilize the BlaI/MecI-DNA complex. We propose a general model, in which the acylation of BlaR/MecR receptor and the cellular stress induced by the antibiotic, are both necessary to generate a cell wall-derived coactivator responsible for the expression of an inducible ?-lactam-resistance factor. The new model proposed confirms and emphasizes the role of peptidoglycan degradation fragments in bacterial cell regulation.
Project description:Bacillus licheniformis strain TAB7 is a bacterium used as a commercial deodorizing agent for compost in Japan. In this work, its ability to biotransform the following monocyclic phenolic compounds was assessed: ferulate, vanillate, p-coumarate, caffeate, protocatechuate, syringate, vanillin, and cinnamate (a precursor for some phenolic compounds). These compounds are abundant in composting material and are reported to have allelopathic properties. They come from sources such as plant material decomposition or agro-industrial waste. Biotransformation assays were carried out in LB supplemented with 0.2 mg/mL of an individual phenolic compound and incubated for up to 15 days followed by extraction and HPLC analysis. The results showed that TAB7 could biotransform ferulate, caffeate, p-coumarate, vanillate, protocatechuate, and vanillin. It, however, had a poor ability to transform cinnamate and syringate. LC-MS/MS analysis showed that ferulate was transformed into 4-vinylguaiacol as the final product, while caffeate was transformed into 4-ethylcatechol. TAB7 genome analysis suggested that, while TAB7 may not mineralize phenolic compounds, it harbored genes possibly encoding phenolic acid decarboxylase, vanillate decarboxylase, and some protocatechuate degradation pathway enzymes, which are involved in the catabolism of phenolic compounds known to have negative allelopathy on some plants. The results thus suggested that TAB7 can reduce such phenolic compounds in compost.
Project description:Here, we report the draft genomes of twelve isolates of five different Bacillus species, all spore-forming, Gram-positive bacteria.
Project description:BACKGROUND:A promoter that drives high-level, long-term expression of the target gene under substrate limited growth conditions in the absence of an artificial inducer would facilitate the efficient production of heterologous proteins at low cost. A novel phosphate-regulated expression system was constructed using the promoter of the phytase encoding gene phyL from Bacillus licheniformis for the overexpression of proteins in this industrially relevant host. RESULTS:It is shown that the phyL promoter enables a strong overexpression of the heterologous genes amyE and xynA in B. licheniformis when cells were subjected to phosphate limitation. Whether B. licheniformis can use phytate as an alternative phosphate source and how this substrate influences the PphyL controlled gene expression under growth conditions with limited inorganic phosphate concentrations were also investigated. It is shown that B. licheniformis cells are able to use sodium phytate as alternative phosphate source. The addition of small amounts of sodium phytate (? 5?mM) to the growth medium resulted in a strong induction and overexpression of both model genes in B. licheniformis cells under phosphate limited growth conditions. CONCLUSIONS:The PphyL controlled expression of the investigated heterologous genes in B. licheniformis is strongly auto-induced under phosphate limited conditions. The proposed PphyL expression system enables an overexpression of target genes in B. licheniformis under growth conditions, which can be easily performed in a fed-batch fermentation process.