Use of waste materials for Lactococcus lactis development.
BACKGROUND
Lactococcus lactis is an interesting microorganism with several industrial applications, particularly in the food industry. As well as being a probiotic species, L. lactis produces several metabolites with interesting properties, such as lactic acid (LA) and biosurfactants. Nevertheless, L. lactis is an especially demanding species since it has strong nutritional requirements, implying the use of complex and expensive culture media.


RESULTS
The results showed the potential of L. lactis CECT-4434 as a LA and biosurfactant producer. The economical cost of L. lactis cultures can be reduced by replacing the MRS medium by the use of two waste materials: trimming vine shoots as C source, and 20 g L(-1) distilled wine lees (vinasses) as N, P and micronutrient sources. From the hemicellulosic fraction, 14.3 g L(-1) LA and 1.7 mg L(-1) surfactin equivalent were achieved after 74 h (surface tension reduction of 14.4 mN m(-1)); meanwhile, a simultaneous saccharification and fermentation process allowed the generation of 10.8 g L(-1) LA and 1.5 mg L(-1) surfactin equivalent after 72 h, reducing the surface tension by 12.1 units at the end of fermentation.


CONCLUSIONS
Trimming vine shoots and vinasses can be used as alternative economical media for LA and cell-bound biosurfactant production.
Rodríguez
Noelia
N
Department of Chemical Engineering, Sciences Faculty, University of Vigo (Campus Ourense), As Lagoas s/n, Ourense, Spain.
Torrado
Ana
A
Cortés
Sandra
S
Domínguez
José Manuel
JM
D002244:Carbon / Q000378:metabolism; D003470:Culture Media / Q000191:economics; D046508:Culture Techniques / Q000379:methods; D005285:Fermentation; D019649:Food Industry; D005947:Glucose / Q000378:metabolism; D007220:Industrial Waste; D019344:Lactic Acid / Q000096:biosynthesis*; D013294:Lactococcus lactis / Q000254:growth & development* / Q000378:metabolism; D018977:Micronutrients / Q000378:metabolism; D018520:Plant Shoots; D011134:Polysaccharides / Q000378:metabolism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000378:metabolism*; D027843:Vitis; D014920:Wine
D003470:Culture Media; D007220:Industrial Waste; D018977:Micronutrients; D011134:Polysaccharides; D013501:Surface-Active Agents; D019344:Lactic Acid; D002244:Carbon; C007916:hemicellulose; D005947:Glucose