Solid-state fermentation production of L-lysine by Corynebacterium glutamicum (ATCC 13032) using agricultural by-products as substrate.

To meet the growing demand for L-lysine, an essential amino acid with various applications, it is crucial to produce it on a large scale locally instead of relying solely on imports. This study aimed to evaluate the potential of using Corynebacterium glutamicum ATCC 13032 for L-lysine production from agricultural by-products such as palm kernel cake, soybean cake, groundnut cake, and rice bran. Solid-state fermentation was conducted at room temperature for 72 h, with the addition of elephant grass extract as a supplement. The results revealed that these agricultural by-products contain residual amounts of L-lysine. By employing solid-state fermentation with C. glutamicum (106 CFU/ml) in 100 g of various agricultural by-products, L-lysine production was achieved. Interestingly, the addition of elephant grass extract (1 g of elephant grass: 10 ml of water) further enhanced L-lysine production. Among the tested substrates, 100 g of groundnut cake moistened with 500 ml of elephant grass extract yielded the highest L-lysine concentration of 3.27 ± 0.02 (mg/gds). Furthermore, fermentation led to a substantial rise (p < 0.05) in soluble protein, with solid-state fermented soybean cake moistened with 500 ml of elephant grass extract exhibiting the highest amount of 7.941 ± 0.05 mg/gds. The activities of xylanase, amylase and protease were also significantly enhanced. This study demonstrates a viable biotechnological approach for locally producing L-lysine from agricultural by-products using solid-state fermentation with C. glutamicum. The findings hold potential for both health and industrial applications, providing a sustainable and economically feasible method for L-lysine production.

Solid-state fermentation of cassava (Manihot esculenta Crantz): a review.

Solid-state fermentation (SSF) is a promising technology for producing value-added products from cassava (Manihot esculenta Crantz). In this process, microorganisms are grown on cassava biomass without the presence of free-flowing liquid. Compared to other processing methods, SSF has several advantages, such as lower costs, reduced water usage, and higher product yields. By enhancing the content of bioactive compounds like antioxidants and phenolic compounds, SSF can also improve the nutritional value of cassava-based products. Various products, including enzymes, organic acids, and biofuels, have been produced using SSF of cassava. Additionally, SSF can help minimize waste generated during cassava processing by utilizing cassava waste as a substrate, which can reduce environmental pollution. The process has also been explored for the production of feed and food products such as tempeh and cassava flour. However, optimizing the process conditions, selecting suitable microbial strains, and developing cost-effective production processes are essential for the successful commercialization of SSF of cassava.

Biochemical characterization of solid-state fermented cassava roots (Manihot esculenta Crantz) and its application in broiler feed formulation.

The biochemical parameters of solid-state fermented peeled and unpeeled cassava roots (Manihot esculenta Crantz) and their application in broiler feed formulations were investigated. Fermentation occurred at room temperature for 72 h (pH 3-9). The samples utilized for five (5) broiler starter feeds were labeled: control, unfermented unpeeled cassava (UUC), unfermented peeled cassava (UPC), fermented unpeeled cassava (FUC), and fermented peeled cassava (FPC). Formulations were made by substituting fermented/non-fermented cassava roots at pH 7 for maize (w/w%). Fermentation-induced changes included increased soluble and total protein concentrations (69.3 and 334.5 mg/g) and (9.6 and 10.8%), respectively, in cultures prepared with peeled and unpeeled cassava at pH 7 compared to the control (p < 0.05), and a reduction (p < 0.01) in cyanide concentration from 44.4 to 78.7 mg/kg in the control to 8.5 and 13.7 mg/kg in fermented cassava at pH 7. Birds fed FUC and FPC meal (0.6 and 0.5 kg) gained significantly more weight (p < 0.05) than those fed the control (0.3 kg). The biochemical parameters aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and urea levels in broiler serum did not differ significantly (p > 0.05) for birds fed with fermented peeled and unpeeled cassava. Conversely, serum albumin and calcium levels were significantly lower (p < 0.05) for birds fed with the control feed compared to birds fed with fermented feeds. The results imply that fermented peeled and unpeeled cassava roots could be a safe and nutritionally beneficial replacement for maize in broiler diet.

Influence of farmyard manure on some morphological and biochemical parameters of cowpea (Vigna unguiculata) seedling grown in cadmium-treated soil.

The present study aims to assess the effects of the two kinds of farmyard manure (poultry and pig manures) as amendments for soil on cadmium (Cd) toxicity in plants using cowpea seedlings as plant model. Cd toxicity was evaluated by assessing the effect of the metal on the growth rate and antioxidant status as well as the ability of the plant to metabolise xenobiotic. There was a significantly (p < 0.05) increased concentration of Cd in the root, stem and leaves of cowpea seedlings grown in all the treated soils relative to control. Addition of poultry manure to the soil significantly (p < 0.05) decreased the level of Cd in these component parts of the seedlings and their corresponding bioaccumulation factor in a dose-dependent manner as compared with treatments with Cd pollution without manure addition and Cd pollution with pig manure addition. There was restoration of Cd-induced effect on growth rate parameters to levels comparable to controls in cowpea seedlings grown in Cd-treated soil augmented with poultry manure but not in cowpea seedlings in cadmium-treated soil with pig manure amendments. Similarly, augmentation of Cd-treated soil with pig manure did not alter the Cd-induced effect on the levels of superoxide dismutase (SOD) and lipid peroxidation (LPO) in leaf, stem and roots, as SOD remained significantly (p < 0.05) decreased and LPO increased relative to control. On the other hand, the levels of SOD and LPO in these parts of cowpea seedlings grown in Cd-treated soils amended with poultry manure were restored to a level not significantly (p > 0.05) different from control. Like in the case of SOD, the Cd-induced inhibition of the activity of xenobiotic metabolising enzymes, aldehyde oxidase and sulphite oxidase remained significantly (p < 0.05) decreased in the organs of seedling grown in Cd-treated soil amended with pig manure. Conversely, the Cd-induced effect on the activities of these enzymes was reversed in the organs of seedlings exposed to Cd and poultry manure as it was not significantly (p > 0.05) different from control. In conclusion, the findings of the study revealed that supplementation of Cd-treated soils with pig and poultry manures reversed effects of Cd on cowpea seedlings. However, poultry manure was more effective than pig manure in ameliorating the effects of Cd.

Effect of a controlled food-chain mediated exposure to cadmium and arsenic on oxidative enzymes in the tissues of rats.

OBJECTIVE: The present study aims to investigate the effect of cadmium and arsenic through a controlled food chain on the activities of some oxidative enzymes (Sulphite oxidase SO, Aldehyde oxidase AO, Monoamine oxidase MO and Xanthine oxidase, XO) in the liver, kidney, testes, heart and brain of rats. MATERIALS AND METHODS: Fish (the first trophic level) were exposed to both metals (singly and in mixture) using cadmium chloride (CdCl2) as the source of cadmium and arsenic trioxide (AS2O3) as the source of arsenic at a concentration of 0.4 mg of metals/100 ml of water for 1 month and then sacrificed. The contaminated fish were then used as a source of protein in compounding the experimental diet to which the rats (the second trophic level) were exposed to for a period of 1 and 3 months. The Cd- and As-load in the feed and tissues of rats as well as the activities of the oxidative enzymes were subsequently analyzed in the various tissues after both period of exposure. RESULTS: Metal analysis on the tissues of rats showed that the metals accumulated more in the liver than in other organs after the 1 month exposure but accumulated more in the kidney after the 3 months exposure. The activities of the oxidative enzymes in the liver were significantly (P < 0.05) decreased in all test groups after the 1 and 3 months exposure. However, after the 1 month exposure, the kidney, testes and heart showed an initial increase in the activities of these enzymes which were decreased after the 3 months exposure. In the brain, the activities of these enzymes were increased in both duration of study. CONCLUSION: From the results obtained in the current study, it could be concluded that exposure to cadmium and arsenic through the food chain leads to accumulation of these metals in the tissues of experimental rats leading to the inhibition of oxidative enzymes, thus affecting several normal metabolic processes.