Characterization of mannitol producing strains of Leuconostoc species

Abstract

Mannitol is a naturally occurring low calorie sweetener, widely used in the food, pharmaceutical, medicine and chemical industries. In this study mannitol producing strains of Leuconostoc spp. (210) were isolated from a wide array of sources such as raw milk, fermented milks, fermented cereal foods, fruits, vegetables and sugar factory syrup. During initial screening, half of the population of these isolates (105) exhibited ability to produce mannitol to a variable extent. Only 11.4% isolate produced mannitol yield of above 80% (when fructose used @ 50 g/ l). Cultural and environmental factors affecting growth and mannitol production were studied for four high mannitol producing isolates. High mannitol production was favored by high temperature and high pH. Isolates had high osmotic tolerance as these could use fructose concentration as high as 100 g/l in batch culture. Sequencing of 16S rRNA genes of the strains revealed that Ln27, Ln104 and Ln206 were Leuconostoc mesenteroides and Ln92 was Leuconostoc fallax.

Characterization of Glucansucrases and Fructansucrases Produced by Wild StrainsLeuconostoc MesenteroidesURE13 andLeuconostoc MesenteroidesLM17 Grown on Glucose or Fructose Medium as a Sole Carbon Source

“…consequently, it could be assumed that the studied strains are mannitol + . our preliminary results are in agreement with those of Kim et al (17) and Patra et al (33). it could be hypothesized that our strains have the potential to be used in further studies dealing with the production of fructans and mannitol.…”

“…Four of these strains produced FS of approximately 130 kDa in medium with or without sucrose (44). Several heterofermentative lAB belonging to the genera Lactobacillus and Leuconostoc have been studied for production of mannitol from fructose and sucrose (33,41). For heterofermentative lAB, fructose acts as an electron acceptor for regeneration of nAD + and such strains contain nAD(P)h mannitol dehydrogenase (MDh) (49).…”

Lactobacillus reuteri CRL 1101 highly produces mannitol from sugarcane molasses as carbon source

“…Saha and Nakamura (2003) reported on the ability to produce mannitol from fructose by strains of Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus cellobiosus, Lactobacillus fermentum, Lactobacillus intermedius, Leuconostoc amelibiosum, Leuconostoc citrovorum, Leuconostoc mesenteroides and Leuconostoc paramesenteroides. Recently, Patra et al (2011) characterized different mannitol-producing strains of Leuconostoc isolated from a broad range of raw and indigenous fermented foods. The strain L. intermedius NRRL B-3693 selected by Saha and Nakamura (2003) was able to produce up to 198 g/l of mannitol from a high fructose concentration (300 g/l) medium.…”

Characterization of the microbial diversity in yacon spontaneous fermentation at 20°C

“…This analysis additionally showed that the community of Lactobacillales is dominated by Leuconostoc species, presumably due to the low percentage of salt added in the cover brine (2%). Species of Leuconostoc are commonly found in fruits and vegetables and they play important roles in the fermentation of dairy products, vegetables and meats given their ability to ferment sugars (sucrose, glucose, fructose) producing lactic acid, glucans, fructans, and mannitol (Groben et al, 2001; Kim et al, 2002; Patra et al, 2011). …”