Pomegranate peel waste: a new substrate for citric acid production by Aspergillus niger in solid-state fermentation under non-aseptic conditions.

Citric acid production from dried and non-dried pomegranate peel wastes by the fungus Aspergillus niger B60 in solid-state fermentation (SSF) under non-aseptic conditions was investigated. The maximum amount of citric acid (278.5 g/kg dry peel) was achieved using dried (at 45 °C for 48 h) pulverized pomegranate peels with moisture content 75% and initial pH 8.

Carotene production from waste cooking oil by in a bubble column reactor: The role of oxidative stress.

The oxidative stress induced by hydroperoxides and reactive oxygen species (ROS) during carotene production from waste cooking oil (WCO) and corn steep liquor (CSL) by the fungus in a bubble column reactor was investigated. The specific activities of the intracellular enzymes superoxide dismutase (SOD) and catalase (CAT) as well as the micromorphology of the fungus were measured in order to study the response of the fungus to oxidative stress. The changes of the morphology of microorganism leaded to pellets formation and documented using a computerized image analysis system.

Waste cooking oil: A new substrate for carotene production by Blakeslea trispora in submerged fermentation.

The objective of this study was to evaluate a waste, waste cooking oil (WCO) as substrate for carotene production by Blakeslea trispora in shake flask culture. WCO was found to be a useful substrate for carotene production. B.

The role of oxidative stress on carotene production by Blakeslea trispora in submerged fermentation.

In aerobic metabolism, reactive oxygen species (ROS) are formed during the fermentation that can cause oxidative stress in microorganisms. Microbial cells possess both enzymatic and non-enzymatic defensive systems that may protect cells from oxidative damage. The antioxidant enzymes superoxide dismutase and catalase are the two key defensive enzymes to oxidative stress.

From cheese whey to carotenes by Blakeslea trispora in a bubble column reactor.

The effect of the aeration rate on carotene production from deproteinized hydrolyzed whey by Blakeslea trispora in a bubble column reactor was investigated. Aeration rate significantly affected carotene concentration and morphology of the fungus. Enhanced aeration caused change of the morphology of B.

Oxidative stress response of Blakeslea trispora induced by iron ions during carotene production in shake flask culture.

The adaptive response of the fungus Blakeslea trispora to the oxidative stress induced by iron ions during carotene production in shake flask culture was investigated. The culture response to oxidative stress was studied by measuring the specific activities of catalase (CAT) and superoxide dismutase (SOD). The addition of 1.

Stimulation of the biosynthesis of carotenes by oxidative stress in Blakeslea trispora induced by elevated dissolved oxygen levels in the culture medium.

The adaptive response of the fungus Blakeslea trispora to the oxidative stress induced by elevated dissolved oxygen concentrations during carotene production was investigated by measuring the specific activities of catalase (CAT) and superoxide dismutase (SOD) and the micromorphology of the fungus using a computerized image analysis system. Changes in the ratio of the volume of air (V(a)) over the medium and the volume of medium (V(m)) in the flask caused changes of the morphology of microorganism from clumps to pellets and increases in the specific activities of CAT and SOD. The oxidative stress in B.

Autolysis of Blakeslea trispora during carotene production from cheese whey in an airlift reactor.

The phenomenon of autolysis in Blakeslea trispora during carotene production from deproteinized hydrolyzed whey in an airlift reactor was investigated. The process of cellular autolysis was studied by measuring the changes in carotene concentration, dry biomass, residual sugars, pH, intracellular protein, specific activity of the hydrolytic enzymes (proteases, chitinase), and micromorphology of the fungus using a computerized image analysis system. All these parameters were useful indicators of autolysis, but image analysis was found to be the most useful indicator of the onset and progress of autolysis in the culture.

Oxidative stress response and morphological changes of Blakeslea trispora induced by butylated hydroxytoluene during carotene production.

The adaptive response of the fungus Blakeslea trispora to the oxidative stress induced by butylated hydroxytoluene (BHT) during carotene production in shake flask culture was investigated. The culture response to oxidative stress was studied by measuring the specific activities of catalase (CAT) and superoxide dismutase (SOD) and the micromorphology of the fungus using a computerized image analysis system. The addition of exogenous BHT to the medium caused changes of the morphology of microorganism from aggregates with large projected area to aggregates with small projected area.

Production of beta-carotene from beet molasses by Blakeslea trispora in stirred-tank and bubble column reactors: development of a mathematical modeling.

The effect of aeration rate and agitation speed on beta-carotene production from molasses by Blakeslea trispora in a stirred-tank fermentor and optimization of the production of the pigment in a bubble column reactor were investigated. In addition, a central composite design was employed to determine the maximum beta-carotene concentration at optimum values for the process variables (aeration rate, sugar concentration, linoleic acid, kerosene). By image analysis of the morphology of the fungus, a quantitative characterization of the hyphae and zygospores formed was obtained.

Production and characterization of pullulan from beet molasses using a nonpigmented strain of Aureobasidium pullulans in batch culture.

The production of pullulan from beet molasses by a pigment-free strain of Aztreobasidium pullulans on shake-flask culture was investigated. Combined pretreatment of molasses with sulfuric acid and activated carbon to remove potential fermentation inhibitors present in molasses resulted in a maximum pullulan concentration of 24 g/L, a biomass dry wt of 14 g/L, a pullulan yield of 52.5%, and a sugar utilization of 92% with optimum fermentation conditions (initial sugar concentration of 50 g/L and initial pH of 7.