Co-production of lactic acid and chitin using a pelletized filamentous fungus Rhizopus oryzae cultured on cull potatoes and glucose.
OBJECTIVE
This paper developed a novel process for lactic acid and chitin co-production of the pelletized Rhzious oryzae NRRL 395 fermentation using underutilized cull potatoes and glucose as nutrient source.


RESULTS
Whole potato hydrolysate medium was first used to produce the highest pelletized biomass yield accompanying the highest chitin content in biomass. An enhanced lactic acid production then followed up using batch, repeated batch and fed batch culture with glucose as carbon source and mixture of ammonia and sodium hydroxide as neutralizer. The lactic acid productivity peaked at 2.8 and 3 g l(-1 )h(-1) in repeated batch culture and batch culture, respectively. The fed batch culture had the highest lactate concentration of 140 g l(-1).


CONCLUSIONS
Separation of the biomass cultivation and the lactic acid production is able to not only improve lactic acid production, but also enhance the chitin content. Cull potato hydrolysate used as a nutrient source for biomass cultivation can significantly increase both biomass yield and chitin content.


CONCLUSIONS
The three-step process using pelletized R. oryzae fermentation innovatively integrates utilization of agricultural residues into the process of co-producing lactic acid and chitin, so as to improve the efficiency, revenues and cost of fungal lactic acid production.
Liu
Y
Y
Department of Biological Systems Engineering, and Centre for Bioenergy and Bioproducts, Washington State University, Pullman, WA 99163, USA.
Liao
W
W
Chen
S
S
D000117:Acetylglucosamine / Q000032:analysis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D018929:Cell Culture Techniques / Q000379:methods*; D002686:Chitin / Q000096:biosynthesis*; D003470:Culture Media; D005947:Glucose / Q000378:metabolism*; D019344:Lactic Acid / Q000096:biosynthesis*; D012233:Rhizopus / Q000254:growth & development / Q000378:metabolism*; D011198:Solanum tuberosum / Q000378:metabolism*; D013172:Spores, Fungal / Q000378:metabolism
D003470:Culture Media; D002686:Chitin; D019344:Lactic Acid; D005947:Glucose; D000117:Acetylglucosamine