Conversion of Food waste to Single Cell Protein using Aspergillus Niger

The utilization of food waste into products like single cell protein is an alternative solution to global protein shortage and to alleviate pollution problems. This investigation was carried out with food wastes such as orange, pineapple, banana, watermelon and cucumber waste as growth media for A. niger using standard techniques. Data obtained showed that Banana waste medium gave a higher yield of A. niger biomass and protein content than other waste investigated with values 2.29±0.02 and 0.57±0.01 g/L respectively. Biomass yield from Banana waste medium was statistically significant with the other food waste (p< 0.05). Among the various supplemented nitrogen sources in the Banana waste medium, ammonium nitrate (NH4NO3) gave the highest biomass and protein yield of 3.20±0.02 and 0.79± 0.04 g/L respectively. Thus, the study revealed that A. niger biomass can be produced from food waste and optimal yield can be enhanced by supplementing the medium with ammonium nitrate

Nitrogen supplements effect on amylase production by Aspergillus niger using cassava whey medium

The production of amylase by Aspergillus niger on three cassava whey media in liquid shake culture was compared. The supplemented cassava whey (SCW) medium exhibited gave amylase activity of 495 U/ml. Biomass cropped was 1.63 g/l in the SCW medium. Yeast extract employed as a nitrogensupplement increased biomass yield of A. niger to 2.75 g/l with maximum amylase activity of 643 U/ml. Sodium nitrate (NaNO3) as nitrogen supplement had the lowest biomass yield of 0.77 g/l and amylase activity of 206 U/ml. Thus yeast extract as nitrogen supplement of cassava whey medium supported maximum production of amylase and biomass of A. niger

Antibacterial Metabolites Obtained from Fermentation of Peanut and Cowpea by Lactobacillus spp

Lactic acid bacteria elective habitat is food matrix, where they release encrypted metabolites from several parent proteins as a result of their proteolytic activity in the matrix. These metabolites when decrypted confer different bioactive activity thus improving public health. This study was aimed at producing peptide containing metabolites with antibacterial efficacy from defatted cowpea and peanut using Lactobacillus spp. Lactobacillus spp. isolated from spoilt yoghurt were identified using culture dependent and independent method. The isolates were screened for proteolytic ability on skimmed milk agar. The selected isolate with highest proteolytic activity was used for metabolites production through fermentation of defatted cowpea and peanut at 37 oC for 72 h. Parameters analyzed during fermentation were pH, Lactobacillus count, protease activity, peptide concentration and antibacterial activity. The crude peptides produced were assayed for antibacterial activity against bacteria isolated from spoilt meat. From the identified Lactobacillus spp., L. plantarum CAU4347 had the highest proteolytic activity with clear zone of 24.50 \ub1 0.707 mm. During fermentation the highest and lowest Lactobacillus counts were from cowpea and peanut media with values 294.2 \ub1 0.21 7107 and 0.60 \ub1 0.4 7107 cfu/ml respectively. Cowpea medium inoculated with L. plantarum CAU4347, had the highest peptide concentration of 79.92 \ub1 0.01 \u3bcg/ml. Consequently, peanut medium showed higher antibacterial activity of 18 mm against Escherichia coli . This result finding suggests that encrypted peptide metabolites from cowpea and peanut flour can confer antibacterial activity against meat spoilage bacteria thus could be utilized as a potential bio-preservative

The establishment of a marine focused biorefinery for bioethanol production using seawater and a novel marine yeast strain

Current technologies for bioethanol production rely on the use of freshwater for preparing the fermentation media and use yeasts of a terrestrial origin. Life cycle assessment has suggested that between 1,388 to 9,812 litres of freshwater are consumed for every litre of bioethanol produced. Hence, bioethanol is considered a product with a high-water footprint. This paper investigated the use of seawater-based media and a novel marine yeast strain ‘Saccharomyces cerevisiae AZ65’ to reduce the water footprint of bioethanol. Results revealed that S. cerevisiae AZ65 had a significantly higher osmotic tolerance when compared with the terrestrial reference strain. Using 15-L bioreactors, S. cerevisiae AZ65 produced 93.50 g/L ethanol with a yield of 83.33% (of the theoretical yield) and a maximum productivity of 2.49 g/L/h when using seawater-YPD media. This approach was successfully applied using an industrial fermentation substrate (sugarcane molasses). S. cerevisiae AZ65 produced 52.23 g/L ethanol using molasses media prepared in seawater with a yield of 73.80% (of the theoretical yield) and a maximum productivity of 1.43 g/L/h. These results demonstrated that seawater can substitute freshwater for bioethanol production without compromising production efficiency. Results also revealed that marine yeast is a potential candidate for use in the bioethanol industry especially when using seawater or high salt based fermentation media

The effect of anaerobic digestion on the survival of Salmonella and coliform bacteria

The decline in viable number of Salmonella spp and coliform bacteria was investigated in laboratory based anaerobic and aerobic digestion of cow dung. The results indicated that the unheated anaerobic digestion had a greater reduction in the viable number of Salmonella spp and coliformbacteria 1.05 x 104 cells/ml and 1.26 x 104 cells/ml respectively than the aerobic digestion 4.50 x 106 and 1.58 x 106 cells/ml respectively. The anaerobic and aerobic digestions were found to be temperature dependent. Decrease in temperature from 31±1 to 26±1oC resulted in increase in viable cell count in the digesters. The final pH was found to be 8.10 in the unheated anaerobic digestion. The reduction of Salmonella spp to 1.05 x 104cells/ml showed that anaerobic digestion can help in combating the spread of pathogenic organisms at livestock production sites, abattoirs, meat processing units and farm lands.Keywords: Salmonella spp, coliform bacteria, cow dung, anaerobic and aerobic digestio