Effect of mutation at oxyanion hole residu (H110F) on activity of Lk4 lipase.

Mutant of lipase at oxyanion hole (H110 F) was constructed. The gene was highly expressed in Eschericia coli BL21 (DE3) and the recombinant protein was purified using Ni-NTA affinity chromatography. The activity of mutant enzyme was significantly increased compared to that the wild type. Further comparison showed that both of the enzymes exhibited same optimum pH and temperature, and showed highest lipolytic activity on pNP-decanoate (C10). The wild type appeared lost of activity on C14 and C16 substrates meanwhile the mutant still showed activity up to 20 %. In the presence of non polar organic solvent such as n-hexane, the wild type became inactive enzyme meanwhile the mutant still remained 50 % of its activity. The results suggested that mutation at oxyanion hole (H110 F) caused enzyme-substrate interaction change resulting on elevation of activity, better activity toward longer carbon chain substrate and improving the activity in the present of non polar organic solvent.

Dataset of microbial community structure in alcohol sprayed banana associated with ripening process.

Banana ripening is a complex molecular process that produces visible changes in the texture, aroma, taste and nutritional content. Ripening is controlled by genetic code, metabolic pathway and associated microbiome. We reported the microbial community structure during banana ripening with alcohol treatment to discover endophytic and epiphytic microbes. We observed the pulp and peel from the first and seventh days of Cavendish (Musa acuminata cv. Cavendish) from mature green fruit and treated with 70% alcohol or distilled water sum up to eight samples and applied the 16S rRNA Illumina sequencing from V3-V4 gene region. After quality check 144,368 sequences were obtained in the dataset comprising a total read length of 1,237,805 base pairs. A sum of 199 genera were successfully isolated, with genera Alcaligenes was the most dominant genera at 56.65% and followed by more than 1% were genera Acinetobacter, Enhydrobacter, Pseudomonas, Stenotrophomas, Thermus, and Aerococcus using mothur pipelines. The highest diversity sample with 101 unique genera was belongs to distilled water treated raw bananas peel (NN1K) and the lowest diversity at 38 was belongs to distilled water treated ripe bananas pulp (NN7D). The metagenome data are available at NCBI Sequence Read Archive (SRA) database and Biosample under accession number PRJNA590572. The data contribute to discover different bacterial communities during post-harvest treatment.