Chitinophaga silvatica sp. nov., isolated from forest soil, and reclassification of Chitinophaga extrema as a later heterotypic synonym of Chitinophaga solisilvae.

A novel bacterial strain, designated K2CV101002-2T, was isolated from forest soil collected at Dinghushan Biosphere Reserve, Guangdong Province, PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that it belonged to the genus Chitinophaga and was most closely related to Chitinophaga terrae KP01T (99.0 %), followed by Chitinophaga extrema Mgbs1T (98.3 %) and Chitinophaga solisilvae O9T (98.1 %). The draft genome sequence was 6.8 Mb long with a relative low G+C content of 39.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between the novel strain and closely related type strains were 71.4‒76.2 % and 18.4‒19.6 %, respectively. Meanwhile the corresponding values between C. extrema Mgbs1T and C. solisilvae O9T were 98.6 and 88.1 %, respectively. The novel strain contained iso-C15:0, C16:1 ω5c and iso-C17:0 3-OH as the major fatty acids and MK-7 as the predominant respiratory quinone. The polyphasic study clearly supported that strain K2CV101002-2T represents a new species of the genus Chitinophaga, for which the name Chtinophaga silvatica sp. nov. (type strain K2CV101002-2T=GDMCC 1.1288T=JCM 32696T) is proposed. In addition, Chitinophaga extrema Goh et al. 2020 should be taken as a later heterotypic synonym of Chitinophaga solisilvae Ping et al. 2020.

Monoterpene synthases contribute to the volatile production in tana (Zanthoxylum ailanthoides) through indigenous cultivation practices.

Tana (Zanthoxylum ailanthoides), a perennial deciduous species in the Rutaceae family, possesses leaves with a unique fragrance that indigenous peoples incorporate into their traditional cuisine. In Kalibuan, the cultivated tana trees were pruned repeatedly to maintain a shorter height, which led to the growth of new leaves that were spicier and pricklier. Tana leaves contain a range of volatile terpenoids, and the pungent aroma may arise from the presence of monoterpenoids. To gain insight into the biosynthetic pathway, five candidate monoterpene synthase genes were cloned and characterized using a purified recombinant protein assay. The main product of Za_mTPS1, Za_mTPS2, and Za_mTPS5 is sabinene, geraniol, and (E)-ß-ocimene, respectively. The main product of Za_mTPS3 and Za_mTPS4 is linalool. Real-time PCR analysis revealed that Za_mTPS1 and Za_mTPS5 are expressed at higher levels in prickly leaves of cultivated tana, suggesting that they may contribute to the distinctive aroma of this plant.