Verticillium Wilt of Okra Caused by Verticillium dahliae Kleb. in China

Okra (Abelmoschus esculentus (L.) Moench) has gained more popularity as an economically significant plant for its nutritional and medicinal value, especially in China. During 2014–2016, the root disease of okra was discovered in four okra commercial fields surveyed in China. A fungul was isolated from the infected tissues, and was identified by Verticillium dahliae based on morphological characteristics. Pathogenicity test demonstrated that the fungus was pathogenic on okra, and fulfilled Koch’s postulates. The analysis of three sequences revealed 99–100% identity with the reported V. dahliae strain in GenBank. Neighbor-joining analysis of the gene sequences revealed that the representative isolates were clustered with V. dahliae. To the best of our knowledge, this is the first report of Verticillium wilt of okra in China.

Production of inulinase from Kluyveromyces marxianus using Dahlia tuber extract

Various carbon sources were evaluated for production of inulinase by yeast, Kluyveromyces marxianus MTCC 3995. Highest inulinase activity was observed with Dahlia extract (25.3 nkat mL-1) as carbon source. The enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat mL-1). The yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°C and 120 rpm. Lowest inulinase yield (4.8 nkat mL-1) was seen in the medium containing glucose as C-source. Although varied inulinase levels were noticed on different C- sources, Inulinase: Sucrase (I/S) ratios were noticed to be similar. Among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat mL-1) and peptone (13.8 nkat mL-1). The enzyme was optimally active at pH (4.0) and 50°C. TLC analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. Results suggest that the dahlia extract induced exoinulinase synthesis in Kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.

Inulina a partir de tubérculos de Dahlia imperialis Roetz

The extraction and isolation of inulin was accomplished, from the tubers of Dahlia imperialis Roetz. (Asteraceae), obtaining a yield of 13.7 percent a dry base. The obtained product was identified by means of physical, chemical, chromatographic and spectroscopic methods; its characterization was made according to the patterns of the United States American Pharmacopeia (USP 23). Some were made assays to determine the practical and functional profits of inulin, such as its use as prebiotic food, in the manufacture of fermented milks, with bifidobacteria, specifically Bifidum infantis. In these assays, it was observed that inulin stimulates and promotes the growth of these bacteria