Purpose

Microbial synthesis of carotenoids has gained interest as an alternative to synthetic carotenoid production due to its easy extraction and high yield. The current study investigates the usability of fruit and vegetable waste- ‘mandi’ waste and agricultural waste as growth medium for carotenoid production by different isolated yeast strains.

Methods

In this study, five isolated yeast strains were identified which were able to utilize C5 and C6 sugars. These yeast strains were compared for their carotenoid production and growth properties when cultivated in inexpensive growth media such as, vegetable ‘mandi’-waste and paddy straw hydrolysate (agricultural waste). During the cultivation, optical density (600 nm), cell weight (wet biomass and dry biomass), total sugar and reducing sugar in selected culture media were determined at different time intervals. The microbial carotenoids were extracted in DMSO (Dimethyl sulfoxide) and were finally transferred to hexane for separation by liquid–liquid extraction.

Results

Using ‘mandi’-waste hydrolysate (waste extract), the strains gave best results with biomass ranging from 29 ± 0.18 to 54 ± 0.14 g/L and the maximum carotenoid produced ranged between 38 ± 0.8 and 62 ± 0.93 mg/L.

Conclusion

Based on our results, ‘Mandi’ waste hydrolysate was found to be the most potent source for carotenoid production. This report provides a suitable bioprocess for the production of yeast-carotenoids, using vegetable ‘mandi’ waste (waste extract) and agricultural waste hydrolysates (paddy straw hydrolysate) via sustainable and cost-effective strategy that may be scaled up in future.

Graphic Abstract

中文翻译：

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红曲霉生产类胡萝卜素分离出农业废弃物和“ Mandi”废弃物

目的

微生物合成类胡萝卜素因其易于提取和高收率而成为合成类胡萝卜素生产的替代品而受到关注。目前的研究调查了水果和蔬菜废物（“ mandi”废物和农业废物）作为不同分离酵母菌株生产类胡萝卜素的生长培养基的可用性。

方法

在这项研究中，确定了五个分离的酵母菌株，它们能够利用C5和C6糖。比较了这些酵母菌株在廉价的生长培养基（如蔬菜'Mandi'-废料和稻草水解产物（农业废料））中培养时类胡萝卜素的产生和生长特性。在培养过程中，以不同的时间间隔测定了所选培养基中的光密度（600 nm），细胞重量（湿生物质和干生物质），总糖和还原糖。微生物类胡萝卜素用DMSO（二甲基亚砜）萃取，最后转移到己烷中，通过液-液萃取分离。

结果

使用'mandi'-废物水解物（废物提取物），菌株产生的最佳生物量范围为29±0.18至54±0.14 g / L，产生的最大类胡萝卜素范围为38±0.8至62±0.93 mg / L。

结论

根据我们的结果，发现“ Mandi”废水解物是类胡萝卜素生产的最有效来源。本报告提供了一种适合的生产酵母类胡萝卜素的生物工艺，它可以通过可持续的，具有成本效益的策略来利用蔬菜“曼迪”废物（废物提取物）和农业废物水解产物（稻草水解产物），并且将来可能会扩大规模。

图形摘要