Antimicrobial Agents for Ocular Use: Bacterial, Fungal, Viral, and Protozoal Infections

Sharma, Namrata; Aron, Neelima; Agarwal, Tushar; Sharma, Charu

doi:10.1007/978-3-319-25498-2_11

Cited by 2 publications

(1 citation statement)

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“…Major producing strains are S. natalensis, S. gilvosporeus, S. chattanogenesis and S. lydicus [5, 6]. Natamycin exhibits its antimicrobial effect by disrupting the ergosterol content in fungal cell walls, and therefore is characterized by its wide spectrum of antifungal activity against yeast, molds and protozoa [7, 8]. Accordingly, natamycin has found a wide range of applications in the treatment of skin infections, ophthalmic mycoses, oral candidiasis, vaginal candidiasis, bronchopulmonary infections and many systemic fungal infections [9, 10].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Natamycin production by Streptomyces natalensis in shake-flasks and stirred tank bioreactor under batch and fed-batch conditions

2019

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Background Natamycin is an antifungal polyene macrolide antibiotic with wide applications in health and food industries. Currently, it is the only antifungal food additive with the GRAS status (Generally Regarded as Safe). Results Natamycin production was investigated under the effect of different initial glucose concentrations. Maximal antibiotic production (1.58 ± 0.032 g/L) was achieved at 20 g/L glucose. Under glucose limitation, natamycin production was retarded and the produced antibiotic was degraded. Higher glucose concentrations resulted in carbon catabolite repression. Secondly, intermittent feeding of glucose improved natamycin production due to overcoming glucose catabolite regulation, and moreover it was superior to glucose-beef mixture feeding, which overcomes catabolite regulation, but increased cell growth on the expense of natamycin production. Finally, the process was optimized in 7.5 L stirred tank bioreactor under batch and fed-batch conditions. Continuous glucose feeding for 30 h increased volumetric natamycin production by about 1.6- and 1.72-folds in than the batch cultivation in bioreactor and shake-flasks, respectively. Conclusions Glucose is a crucial substrate that significantly affects the production of natamycin, and its slow feeding is recommended to alleviate the effects of carbon catabolite regulation as well as to prevent product degradation under carbon source limitation. Cultivation in bioreactor under glucose feeding increased maximal volumetric enzyme production by about 72% from the initial starting conditions.

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