Ectopseudomonas guguanensis strain:SRIHER B649 Genome sequencing and assembly

Pseudomonas guguanensis SRIHER B649 was isolated from the oil contaminated waters of Chennai Harbor. It was found to utilize n-hexadecane as its sole carbon source by producing a monorhamnolipid bioemulsifier. n-hexadecane is a major aliphatic component of crude oil in aquatic environments. Crude oil contamination in marine environment generally occurs due to the spillage during the movement of oil tankers, their collision, oil explosion and the release of effluents from oil refineries. Generally, hexadecane is less amenable to biological degradation, which is perhaps due to its C-16 aliphatic structure, influencing lesser volatility. Hence, it often remains as skeletons even after the degradation of other components of crude oil by any microbial population. However, there are certain bacteria which are capable of utilizing hexadecane as their carbon source. One such bacterium is Pseudomonas guguanensis which plays a key role in the biodegradation of n-hexadecane. Thus, whole genome sequencing was carried out in order to identify the rhamnolipid synthesizing genes and to clone these genes to overproduce the bioemulsifier and enhance the hexadecane degradation.

古冠假单胞菌（Pseudomonas guguanensis）SRIHER B649分离自印度金奈港（Chennai Harbor）的石油污染水域。研究发现，该菌株可通过合成单鼠李糖脂生物乳化剂（monorhamnolipid bioemulsifier），以正十六烷（n-hexadecane）作为唯一碳源进行代谢利用。正十六烷（n-hexadecane）是水生环境中石油的主要脂肪族组分。海洋环境中的石油污染通常由油轮航行溢油、船舶碰撞、原油爆炸以及炼油厂废水排放引发。通常情况下，正十六烷较难被生物降解，这可能与其C16脂肪族结构有关，导致其挥发性较低。因此，即便原油中的其他组分已被各类微生物降解，正十六烷往往仍会残留下来。不过，部分细菌能够以正十六烷作为碳源进行代谢利用。古冠假单胞菌便是其中之一，其在正十六烷的生物降解过程中发挥着关键作用。为此，本研究开展了全基因组测序，以鉴定鼠李糖脂合成基因，并通过克隆这些基因实现生物乳化剂的过量生产，进而强化正十六烷的生物降解能力。