George Emrin, Kumar S Nishanth, Jacob Jubi, Bommasani Bhaskara, Lankalapalli Ravi S, Morang P, Kumar B S Dileep
Agroprocessing and Natural Products Division, National Institute for Interdisciplinary Science and Technology (NIIST), Council of Scientific and Industrial Research (CSIR), Thiruvanathapuram, 695 019, Kerala, India.
Appl Biochem Biotechnol. 2015 May;176(2):529-46. doi: 10.1007/s12010-015-1593-3. Epub 2015 Apr 2.
A plant growth-promoting bacterial strain, PM 105, isolated from a tea plantation soil from the North Eastern region of India was identified as Pseudomonas aeruginosa through classical and 16S ribosomal DNA (rDNA) gene sequencing. Further studies with this strain confirmed broad spectrum antifungal activity against ten human and plant pathogenic fungal pathogens viz. Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Candida albicans, Colletotrichum gloeosporioides, Fusarium oxysporum, Pencillium expansum, Rhizoctonia solani, Trichophyton rubrum besides growth-promoting property in cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan). However, no antibacterial property was exhibited by this strain against the four test bacterial pathogens tested in agar overlay method. The crude bioactive metabolites produced by this strain were isolated with three different solvents that exhibited significant antimicrobial and plant growth-promoting activity. Chloroform extract recorded significant antimicrobial and plant growth-promoting activity. Three major compounds viz. 1-hydroxyphenazine, pyocyanin, and phenazine-1-carboxamide were purified and characterized from crude extracts of this strain by various spectral data. The purified compounds recorded prominent antimicrobial activity but failed to establish the plant growth promotion activity in test crop plants under gnotobiotic conditions. Pyocyanin recorded significant antimicrobial activity, and best activity was recorded against T. rubrum (29 mm), followed by P. expansum (28 mm). These results suggest the use of PM 105 as plant growth-promoting agent in crop plants after successful field trials.
从印度东北地区茶园土壤中分离出的一株促进植物生长的细菌菌株PM 105，通过经典方法和16S核糖体DNA（rDNA）基因测序被鉴定为铜绿假单胞菌。对该菌株的进一步研究证实，它对十种人类和植物病原真菌病原体具有广谱抗真菌活性，即黄曲霉、烟曲霉、黑曲霉、管囊曲霉、白色念珠菌、胶孢炭疽菌、尖孢镰刀菌、扩展青霉、立枯丝核菌、红色毛癣菌，此外还具有促进豇豆（豇豆属）和木豆（木豆属）生长的特性。然而，该菌株在琼脂覆盖法中对四种测试细菌病原体未表现出抗菌特性。用三种不同溶剂分离出该菌株产生的粗生物活性代谢产物，这些代谢产物表现出显著的抗菌和促进植物生长的活性。氯仿提取物具有显著的抗菌和促进植物生长的活性。通过各种光谱数据从该菌株的粗提取物中纯化并鉴定出三种主要化合物，即1-羟基吩嗪、绿脓菌素和吩嗪-1-甲酰胺。纯化后的化合物具有显著的抗菌活性，但在无菌条件下的测试作物中未能证实其促进植物生长的活性。绿脓菌素具有显著的抗菌活性，对红色毛癣菌的抑菌圈最大（29毫米），其次是扩展青霉（28毫米）。这些结果表明，在成功进行田间试验后，PM 105可作为作物的植物生长促进剂。
