Biodegradation and decolourization of anaerobically treated distillery spent wash by a novel bacterial consortium.

Gluconic acid (GA) is a multifunctional carbonic acid regarded as a bulk chemical in the food, feed, beverage, textile, pharmaceutical, and construction industries. The favored production process is submerged fermentation by Aspergillus niger utilizing glucose as a major carbohydrate source, which accompanied product yield of 98%. However, use of GA and its derivatives is currently restricted because of high prices: about US$ 1.20–8.50/kg. Advancements in biotechnology such as screening of microorganisms, immobilization techniques, and modifications in fermentation process for continuous fermentation, including genetic engineering programmes, could lead to cost-effective production of GA. Among alternative carbohydrate sources, sugarcane molasses, grape must show highest GA yield of 95.8%, and banana must may assist reducing the overall cost of GA production. These methodologies would open new markets and increase applications of GA.

Biotechnological production of gluconic acid: future implications

Degradation and metabolization of the pigment-melanoidin in distillery effluent by the marine cyanobacterium Oscillatoria boryana BDU 92181

Color removal from distillery spent wash through coagulation using Moringa oleifera seeds: use of optimum response surface methodology.

Xylanase production by Burkholderia sp. DMAX strain under solid state fermentation using distillery spent wash

The effect of soybean oil on the volumetric oxygen transfer coefficient during the cultivation ofAerobacter aerogenes cells is presented. For our aeration-agitation conditions (0.278 vvm and 500 rpm), it has been demonstrated that the use 19% (v/v) of soybean oil enabled a 1.85-fold increase of thekl a coefficient (calculated on a per liter aqueous phase basis). For smaller volumetric oil fractions,kL a increased linearly with the oil loading. Because of the oxygen-vector properties of soybean oil, this oil is able to significantly increase thekL a of a bioreactor.

Enhanced oxygen transfer rates in fermentation using soybean oil-in-water dispersions

Streptomyces viridosporus strain T7A was grown in a mineral medium supplemented with glycerol (0.7%) and lignosulfonate (0.1%). The biodegradation of two different molecular sized lignosulfonates was studied. Determination of lignosulfonate concentration measured by the nitroso-method revealed that S. viridosporus degrades lignosulfonates differently according to their molecular size. Lignosulfonate losses were 10 and 25% for the higher and shorter molecular weights, respectively. Production of lignin peroxidase activity was induced by lignosulfonate and was growth-associated.

Degradation of lignosulfonated compounds by Streptomyces viridosporus strain T7A

The ability of a mixed natural microbial population, collected in an aerated lagoon treating Fluff pulp effluent and Streptomyces viridosporus strain T7A, to degrade lignosulphonate was evaluated. S. viridosporus growing in a mineral medium containing glycerol (7 g/l) and lignosulphonate (1 g/l) allowed 20% of lignosulphonate to be degraded after 18 days of incubation. A culture of the mixed population on culture medium after S. viridosporus growth was unable to degrade lignosulphonate products. Moreover, antagonism between S. viridosporus and the mixed population or between S. viridosporus and the isolated strains from this population was observed. The enhancement of lignosulphonate biodegradation by naturally occurring microorganisms in association with S. viridosporus (bioaugmentation strategy) seems to be difficult.

J. L. Rols

Papers

Enhanced oxygen transfer rates in fermentation using soybean oil-in-water dispersions

Degradation of lignosulfonated compounds by Streptomyces viridosporus strain T7A

Biodegradability of lignosulphonate by Streptomyces viridosporus strain T7A and a mixed natural microbial population : Antagonistic effects