Coproduction of alkaline protease and xylanase from genetically modified Indonesian local Bacillus halodurans CM1 using corncob as an inducing substrate.

The production of corn generates a substantial amount of agro-industrial waste, with corncob accounting for a significant portion of this waste. In this study, we focused on utilizing corncob as a carbon source and inducer to simultaneously produce two valuable industrial enzymes, protease, and xylanase, using a recombinant strain of B. halodurans CM1. Interestingly, xylan-rich corncob not only enhanced the xylanase activity but also induced protease activity of the modified B. halodurans CM1 strain. The effect of corncob concentration on the coproduction of protease and xylanase was investigated. Corncob with 6 % concentration induced protease activity of 1020.7 U/mL and xylanase activity of 502.8 U/mL in a 7 L bioreactor under the condition of 1 vvm aeration, 250 rpm agitation, 37 °C temperature, initial pH 9.0, and 40 h incubation period. The protease produced was an alkalothermophilic enzyme whose highest activity was at pH 12 and 50 °C, and it belonged to a serine protease family. This alkalothermophilic protease's activity to some degree was reduced by Co2+, Mg2+, Fe2+, Zn2+, and K+, but enhanced by Ca2+ and Ni2+ (at 5 mM). The protease was stable even under the presence of a 15 % concentration of acetone, DMSO, ethanol, and isopropyl alcohol. The protease activity at 30 °C was not considerably changed by the presence of detergent, indicating excellent potential as a washing detergent additive. According to these findings, corncob has the potential to be a substrate for the coproduction of protease and xylanase, which have a wide range of industrial uses.

Bioinformatic analysis of the whole genome sequences of SARS-CoV-2 from Indonesia.

BACKGROUND AND OBJECTIVES: In first May 2020, Indonesia has been successfully submitted the first three full-length sequence of SARS-CoV-2 to GISAID database. Until September 10th, 2020, Indonesia had submitted 54 WGS. In this study, we have analyzed and annotated SARS-CoV-2 mutations in spike protein and main proteases. MATERIALS AND METHODS: The Whole Genome Sequence (WGS) of Indonesia were obtained from GISAID data base. The 54 data were taken from March to September 10th, 2020. The sequences corresponded to Spike Protein (SP), 3-chymotrypsin like protease (3CLpro), and papain like protease (PLpro) were selected. The Wuhan genome was used as reference. RESULTS: In total WGS from Indonesia, we found 5 major clades, which dominated as G clade, where the mutation of D614G was found. This D614G was identified as much as 59%, which mostly reported in late samples submitted. Beside D614G mutation, we report three unique mutations: A352S, S477I, and Q677H. Besides, some mutations were also detected in two domains that were expected to be conserved region, the main viral proteases: PLpro (P77L and V205I), 3CLpro (M49I and L50F). CONCLUSION: The analysis of SARS-CoV-2 from WGS Indonesia showed a high genetic variation. The diversity in SARS-CoV-2 may epidemiologically enhance virulence and transmission of this virus. The prevalence of D614G over the time in different locations, indicating that changes in this mutation may related to host infection and the viral transmission. However, some mutations that have been reported in this study were not eligible for the most stable conformation.

Constitutive high level expression of an endoxylanase gene from the newly isolated Bacillus subtilis AQ1 in Escherichia coli.

A xylanolytic bacterium was isolated from the sediment of an aquarium. Based on the 16S rDNA sequence as well as morphological and biochemical properties the isolate was identified and denoted as Bacillus subtilis (B. subtilis) AQ1 strain. An endoxylanase-encoding gene along with its indigenous promoter was PCR amplified and after cloning expressed in E. coli. In E. coli the recombinant enzyme was found in the extracellular, in the cytoplasmic, and in the periplasmic fraction. The specific activity of the extracellular AQ1 recombinant endoxylanase after 24-hour fermentation was very high, namely, 2173.6 ± 51.4 and 2745.3 ± 11 U/mg in LB and LB-xylan medium, respectively. This activity was clearly exceeding that of the native B. subtilis AQ1 endoxylanase and that of 95% homologous recombinant one from B. subtilis DB104. The result shows that the original AQ1 endoxylanase promoter and the signal peptide gave a very high constitutive extracellular expression in E. coli and hence made the production in E. coli feasible.

Characterization of thermostable native alkaline phosphatase from an aerobic hyperthermophilic archaeon, Aeropyrum pernix K1.

This paper reports the characterization of an alkaline phosphatase (AP) from an aerobic hyperthermophilic Archaeon Aeropyrum pernix K1. The native AP was purified into homogeneity. The enzyme is predicted as a homodimeric structure with a native molecular mass of about 75 kDa and monomer of about 40 kDa. Apparent optimum pH and temperature were estimated at 10.0 and above 95 degrees C, respectively. Magnesium ion increased both the stability and the activity of the enzyme. A. pernix AP has been demonstrated as a very thermostable AP, retaining about 76% of its activity after being incubated at 90 degrees C for 5.5 h and 67% of its activity after being incubated at 100 degrees C for 2.5 h, respectively, under the presence of Mg(II). Enzyme activity was increased in addition of exogenous Mg(II), Ca(II), Zn(II), and Co(II).