Yasin Rabia, Rashid Goran M M, Ali Imran, Bugg Timothy D H
Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
Department of Biotechnology, Mirpur University of Science and Technology (MUST), Mirpur, 10250, AJK, Pakistan.
Heliyon. 2023 Aug 25;9(9):e19511. doi: 10.1016/j.heliyon.2023.e19511. eCollection 2023 Sep.
RHA1 was engineered to utilise the cellulose component of lignocellulose, as well as the lignin fraction, by introduction of cellulase genes. The genome of RHA1 was found to contain two β-glucosidase genes, RHA1_ro01034 and RHA1_ro02947, which support growth on cellobiose as growth substrate. Five Gram-positive endocellulase genes and one exocellulase gene were cloned into expression vector pTipQC2, and expressed in RHA1. Endoglucanase activity was detected, with highest activity using , and this recombinant strain grew on minimal media containing 0.5% carboxymethylcellulose (CMC). The RHA1 genome was also found to contain a 3-dehydroshikimate dehydratase gene RHA1_ro01367, which supports growth on quinic acid as growth substrate, and conversion to protocatechuic acid. Therefore, this bacterium shows promise for further engineering to utilise cellulose for conversion to protocatechuic acid-derived bioproducts.
通过引入纤维素酶基因，对RHA1进行工程改造，使其能够利用木质纤维素的纤维素成分以及木质素部分。研究发现，RHA1的基因组包含两个β-葡萄糖苷酶基因，即RHA1_ro01034和RHA1_ro02947，它们支持以纤维二糖作为生长底物进行生长。将五个革兰氏阳性内切纤维素酶基因和一个外切纤维素酶基因克隆到表达载体pTipQC2中，并在RHA1中表达。检测到内切葡聚糖酶活性，使用[此处原文缺失具体底物]时活性最高，并且该重组菌株能够在含有0.5%羧甲基纤维素（CMC）的基本培养基上生长。还发现RHA1基因组包含一个3-脱氢莽草酸脱水酶基因RHA1_ro01367，它支持以奎尼酸作为生长底物进行生长，并将其转化为原儿茶酸。因此，这种细菌在进一步工程改造以利用纤维素转化为原儿茶酸衍生的生物产品方面具有潜力。
