Comparison of yeast strains for batch ethanol fermentation of cheese?whey powder (CWP) solution

Abstract

Aims: To test the suitability of cheese whey powder (CWP) solution for ethanol fermentation and to compare performances of different Kluyveromyces marxianus strains for ethanol fermentation from CWP solution. Methods and Results: Batch ethanol fermentation of cheese whey (CW), CWP and lactose solutions with the same initial sugar contents were compared by using two different K. marxianus strains and the CWP solution was found to be the most suitable substrate. CWP solution was fermented to ethanol using three different yeast strains and DSMZ‐7239 was found to be the most suitable one yielding the highest rate and extent (3·3%, v/v) of ethanol formation. Conclusions: CWP solution and K. marxianus strain of DSMZ‐7239 were found to be more suitable for ethanol fermentation with the highest ethanol yield when compared with the other substrates and the yeast strains tested. Significance and Impact of the Study: CWP can be used as a concentrated form of CW for ethanol fermentations with considerable advantages.

Effective ethanol production from whey powder through immobilizedE. coliexpressingVitreoscillahemoglobin

“…The supernatant was removed and saved as "whey powder solution" (adapted from Ozmihci and Kargi). [17][18][19][20] Yeast extract was obtained from Merck (Darmstadt, Germany), dissolved in distilled water at a concentration of 30 or 50 g/L, and autolcaved.…”

“…10 Ethanol production from cheese whey has been investigated by many groups. [11][12][13][14][15][16][17][18][19][20][21] In some countries (New Zealand, the United States, and Denmark) bioethanol is produced from whey. 9,22 Due to the low lactose content of whey, however, its fermentation yields only about 2-3% (v/v) ethanol; this makes this process unfeasible at an industrial level, because of the costs of distillation.…”

High-Temperature Ethanol Fermentation and Transformation with Linear DNA in the Thermotolerant Yeast Kluyveromyces marxianus DMKU3-1042

“…This species has been reported to grow at 47°C (3), 49°C (20), and even 52°C (6) and to produce ethanol at temperatures above 40°C (14). Moreover, K. marxianus offers additional benefits (36) including a high growth rate (34) and the ability to utilize a wide variety of industrially relevant substrates such as sugar cane, corn silage juice, molasses, and whey powder (17,27,32,42,49). Because of these advantages, K. marxianus is currently being promoted as a viable alternative to S. cerevisiae as an ethanol producer.…”

Repeated batch fermentation of immobilizedE. coliexpressingVitreoscillahemoglobin for long-term use

“…The supernatant is "whey powder solution" (adapted from Ozmihci and Kargi). [9][10][11][12] Whey powder medium (WPM, pH 7.0) was prepared by combining 400 ml of whey powder solution, 100 mL of sterile yeast extract solution (5 g/L), 100 mL of CaCl 2 (50 g/L), 34 and sterile distilled water to give 1 L final volume.…”

“…Previous studies have shown that whey and whey powder can be used for ethanol production by lactose fermenting microorganisms such as Kluyveromyces lactis, Kluyveromyces marxianus and Candida pseudotropicalis. 7,[9][10][11][12][13] There is a great need for effective, low cost, and reusable methodologies for bioethanol production that can be applied at an industrial scale. 14,15 One such methodology, immobilization of microorganims, has been studied extensively in recent years.…”