Beta-cyanoalanine synthase (EC 4.4.1.9) is a cyanide detoxifying enzyme obtained from Pseudomonas straminea isolated from the effluents of Iron and Steel Smelting Company in Ile-Ife, Osun State. The effluent water samples were screened for their ability to detoxify cyanide and isolates obtained were then screened for b-cyanoalanine synthase production. The samples were screened for their ability to detoxify cyanide and isolates obtained were then screened for β-Cyanoalanine Synthase production. The enzyme was purified through Lyophilization, ion exchange chromatography on CM-Sephadex c-25 and Gel filtration on Biogel P-100. The enzyme had a specific activity of 273.75 U/mg with a purification fold of 2.41 and a yield of 28.90. The native molecular weight of the enzyme was estimated as 54.9 KDa and subunit molecular weight of 60.3 KDa. The K m values of the enzyme for sodium cyanide and L-Cysteine were 8.33 ± 0.05 mM and 1.25 ± 0.26 mM respectively while their maximum reaction velocities were 14.705 ± 0.32 MU/ml/min and 0.1 ± 2.48 MU/ml/min respectively. The optimum temperature and pH for activity were determined to be 40 o C and 9.0. The metals tested at the different concentrations of 1 mM, 5 mM and 10 mM enhanced the activity of the enzyme. Inhibition studies on β-Cyanoalanine Synthase Pseudomonas straminea showed that the activity of the enzyme was affected by mercuric chloride, glycine, EDTA and iodoacetamide. The study concluded that β-Cyanoalanine Synthase from Pseudomonas straminea may possess potential bioremediation properties for detoxification of cyanide polluted wastewaters.

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Background: Exposure of potato tubers to light causes accumulation of glycioalkaloids in the tubers and overdose of glycoalkaoids are associated with some toxicity. This study aims to investigate the effect of consuming sunlight exposed tubers of Irish potato on some selected tissues of rats. Methods:Freshly harvested tubers of Solnum tuberosum were purchased from a farmland and were randomly grouped into five groups. Groups 1- 4 consisted of tubers exposed to sunlight (including visible and invisible light e.g. ultraviolet) for a period of 1, 2, 3, and 4 week(s), respectively, while group 5 served as the control and consisted of freshly harvested tubers of Irish potato that have not been exposed to sunlight. The glycoalkaloids content was determined in both the non-exposed (control) and sunlight exposed tubers. Thereafter the tubers were formulated as diet and administered to rats. Biochemical analyses on serum lipid profile, enzymes of selected tissues (serum, liver, and kidney) and lipid peroxidation were carried out. Results: The results showed that the total glycoalkaloids content of the exposed sunlight groups (230, 250, 270, and 300 mg/kg fresh weight, respectively) significantly increased compared to the control group (100 mg/kg fresh weight). A significant reduction (P < 0.05) in activities of alanine aminotransferase, aspartate aminotransferase and a significant upsurge (P < 0.05) in alkaline phosphatase activity was observed in the selected tissues of sunlight-exposed potato tuber animal groups compared to the (non-exposed) group. Lipid peroxidation assessment revealed a significant upsurge (P < 0.05) in malondialdehyde formation and a mild alteration in serum lipid profile. Conclusion: The study concluded that consumption of sunlight exposed Solanum tuberosum tubers may pose a threat on vital organs of the body irrespective of duration of exposure.

Microorganisms are increasingly being used in cyanide bioremediation. Several organisms have been reported to thrive in cyanide contaminated wastewater due to their ability to produce cyanide detoxifying enzymes. However, to improve the production efficiency of these enzymes combinations of process variables need to be optimized. In this study, Klebsiella oxytoca JCM 1665 was isolated from industrial wastewater, identified by sequencing its 16S rRNA gene and subjected to rhodanese production using submerged fermentation. The conditions for production were optimized using response surface methodology (RSM). Central composite design was employed to evaluate the effects of three production parameters – peptone (1 – 5 %), KCN (0.1 – 0.5 %), and time of incubation (1 – 24 h). Second-order polynomial model was used to predict the response. Rhodanese activity in the experiments varied from 0.05 to 7.5 RU.mg-1.  Under the optimum conditions of 4.35 % peptone, 0.4 % KCN and incubation time of 13 hr., the value for rhodanese yield was 7.810 U.mL-1.  The R2 value for the model was 0.9925 (R2 = 0.9925). Also, the experimental values are in accordance with those predicted, indicating the suitability of the employed model and the success of RSM in optimizing the production conditions.