Comparative Genomics, Transcriptome, and Prokaryotic Expression Analysis of alkB1_1 in Acinetobacter vivianii KJ-1: Revealing the Mechanism of Petroleum Hydrocarbon Degradation

The present study aimed to comprehensively dissect the petroleum hydrocarbon degradation mechanism of <i>Acinetobacter vivianii</i> KJ-1. The isolated and identified strain was able to proliferate using diesel as the sole carbonaceous substrate. Via comparative genomics, an in-depth analysis was performed to elucidate the genome similarities and disparities between this strain and related strains, thereby uncovering a core genome as well as genes with uncharacterized functions. Transcriptome analysis, carried out under different substrate conditions (C16, diesel, sodium acetate) manifested distinct gene expression modalities. A multitude of genes associated with alkane metabolism were differentially expressed, among which <i>alk</i>B1_1 and <i>alk</i>B1_2 was conspicuously upregulated. Prokaryotic expression of <i>alk</i>B1_1 was implemented, and the enzyme activity of the recombinant protein peaked at a pH level of approximately 7.0 and within a temperature range of 30 to 40 °C. The recombinant strain was shown to possess the ability to degrade n-hexadecane. Collectively, this research not only augments the understanding of the degradation mechanism of <i>A. vivianii</i> KJ-1 but also provides a fundamental basis for developing bioremediation strategies targeting petroleum hydrocarbon-contaminated environments.