Abstract

The diversity and biotechnological potential of the haloalkaliphilic actinomycetes of the saline habitats are explored only in a limited sense. Albeit, they have been reported to produce various enzymes, organic acids, antibiotics, and other secondary metabolites. Therefore, we aimed to investigate marine actinomycetes with respect to their cultivation, morphology, biochemical properties, enzyme secretion, solvent tolerance, antibacterial activities and phylogeny. Further, the composition of cell wall and its sugar constituents and variation in multiple–antibiotic-resistance (MAR) suggested diversity of the actinomycetes of the studied habitats. In total, 20 haloalkaliphilic actinomycetes were identified and studied further. Based on the 16S rRNA gene sequences, most of these actinomycetes belong to the genus Nocardiopsis. However, Hae III restriction patterns of the 16S rRNA genes reveal eight main clusters, corresponding with the Jaccard’s similarity coefficient and phenograms based on the biochemical properties. The Canonical Correlation Analysis suggests that pH and temperature rather than salinity and conductivity of the saline habitat are determinants of the growth of actinomycetes. The polyphasic analysis was highly significant in judging the diversity and taxonomy of the marine actinomycetes. Besides, the evaluated phenetic attributes may help in the exploration of the biotechnological potential of these actinomycetes.

摘要

仅在有限的意义上探索盐生境的卤代嗜碱放线菌的多样性和生物技术潜力。尽管已经报道它们会产生各种酶，有机酸，抗生素和其他次级代谢产物。因此，我们旨在研究海洋放线菌的培养，形态，生化特性，酶分泌，耐溶剂性，抗菌活性和系统发育。此外，细胞壁的组成及其糖成分以及多重抗药性（MAR）的变化表明所研究生境的放线菌具有多样性。总共鉴定出20种嗜盐放线菌并进一步研究。基于16S rRNA基因序列，这些放线菌大多数属于诺卡氏菌属。然而，16S rRNA基因的Hae III限制性酶切图谱显示了8个主要簇，与基于生化特性的Jaccard相似系数和象形图相对应。典型相关分析表明，pH和温度而不是盐碱生境的盐度和电导率是放线菌生长的决定因素。多相分析在判断海洋放线菌的多样性和分类学方面非常重要。此外，评估的物候特性可能有助于探索这些放线菌的生物技术潜力。