Synthesis of Antibiotic Penicillin-G Enzymatically by Penicillium chrysogenum

Penicillin-G antibiotic was used as the basic ingredient of making antibiotic type β-lactam such as tetracycline, amoxicillin, ampicillin and other antibiotics. Penicillin-G was splited into 6-amino penicillanic acid as the source of β-lactam. The biosynthetic pathway for the formation of penicillin-G in Penicillium chrysogenum cell through the formation of intermediates was carried out in the form of amino acids such as α-aminoadipate, L-cysteine, L-valine which are formed from glucose (food ingredients).The formation of 6-amino penicillanic acid is an amino acid combination of L-cysteine and L-valine, a step part of the formation of antibiotic penicillin-G in P. chrysogenum cells, thus, it is obvious that there are enzymes involved in its formation. The objective of this study was to examine the use of enzymes present in P. chrysogenum cells to produce penicillin-G and 6-amino penicillanic acid using the intermediate compounds α-aminoadipate, L-cysteine, L-valine and phenylacetic acid assisted by NAFA® coenzymes in P. chrysogenum cells which is more permeable. The research method started from producing biomass of P. chrysogenum cells that demonstrated penicillin-producing antibiotic capability, as the source of the enzyme, followed by addition of permeability treatment of P. chrysogenum cell membrane to get immobile of enzyme by its own cell therefore it can be used more than once. After that the enzyme activity was proven by adding α-aminoadipate, L-cysteine, L-valine, phenylacetic acid and NAFA® coenzyme for the formation of penicillin-G, whereas the addition of L-cystein, L-valine and NAFA® coenzyme were aimed to form 6-amino penicillanic acid. The results showed that P. chrysogenum is able to produce antibiotics with stationary early phase on day 6. The best increased permeability of P. chrysogenum cell membranes was obtained using a 1:4 of toluene:ethanol ratio mixture with the highest antibiotic concentration (130.06 mg/L) after testing for the enzymatic formation of antibacterial penicillin-G.

Effect of dietary Phytase and NSP-degrading enzymes in diets containing rape seed meal on broiler performance

In comparison to 44% crude protein of soybean meal (SBM), the protein content of rapeseed meal (RSM) is about 35-40% and has a physiologically suitable amino acid combination in animal nutrition, but RSM contains nutritionally unfavourable substances such as glucosinolates, sinapin, tannin, phytate and non starch polysaccharides (NSP) (Kocher et al., 2000). Enzymes have the potential to be used in diets contain antinutritional factors that hinder nutrient availability. NSPs include cellulose, B-glucans, arabinoxylans, and pectins that may increase viscosity of digesta and cause a decrease in nutrient digestibility and performance of broiler chickens. Phytase activity from digestive secretions, some feed ingredients, resident bacteria, exogenous microorganisms, or both resident bacteria and exogenous microorganisms is present in the digestive tract of broiler chickens (Kornegay, 2001), but its efficiency at a practical level is very low. It is accepted that broilers lack sufficient levels of phytase activity to effectively hydrolyse the phytate molecule. Phytate-bound P is not well digested, so inorganic P is added to broiler diets that increased feed costs (Lescoat et al., 2005). The purpose of this study was to investigate the replacement value of SBM with locally grown RSM and two types of enzymes (NSP-degrading and phytase) on performance of broiler chickens.

Comparative effects of amino acids and glucose on insulin secretion from isolated rat or mouse islets

Glucose and the combination of leucine and glutamine were used to stimulate insulin secretion from rat islets during a dynamic perifusion and the responses obtained were compared with those elicited from mouse islets under identical conditions. In rat islets, glucose (15 mM) or the amino acid combination of 10 mM glutamine plus 20 mM leucine were most efficacious and peak second-phase insulin release responses were 20- to 30-fold above prestimulatory rates. In contrast to rat islet responses, sustained second-phase insulin secretory responses to the same agonists were minimally increased 1- to 2-fold from mouse islets. Parallel studies demonstrated that phospholipase C (PLC) was markedly activated in rat, but not mouse, islets by both high glucose concentrations and the amino acid combination. Additional studies documented that glucose and amino acid responses of both rat and mouse islets were amplified by carbachol or forskolin. However, wortmannin, a phosphatidylinositol 3-kinase inhibitor, amplified only the responses to glucose leaving the responses to the amino acid mixture unaltered. These observations support the concept that mitochondrial metabolism alone is minimally effective in stimulating insulin secretion from islets. The activation of the supplementary second messenger systems (PLC and/or cAMP) appears essential for the emergence of their full secretory potential. The mechanism regulating the potency and specificity of wortmannin’s impact on glucose-induced secretion remains to be identified; however a unique mechanism is supported by these findings.

STUDIES ON THE METABOLISM OF STREPTOMYCES GRISEUS IN RELATION TO THE PRODUCTION OF STREPTOMYCIN

A synthetic medium inducing high streptomycin production was evolved by studying growth factor and nitrogen requirements of the mold Streptomyces griseus. It was concluded that mycelium growth and streptomycin production do not necessarily parallel each other. Histidine appeared to affect both streptomycin and mycelium formation and was essential in any amino acid combination to induce either a high mycelium or streptomycin yield. Valine was shown to stimulate streptomycin synthesis and aspartic or glutamic promoted only mycelium production. Experiments were done to show which metabolic changes in the medium could be associated with growth and which with the antibiotic production.The effect on the mold of high concentration of sodium chloride was investigated. It was found that by reducing the amount of salt in the nutrient media, the greater part of the streptomycin could be recovered from the mycelium instead of the medium. It appears that the antibiotic is a product of intracellular synthesis, since ions of the lyotropic series affecting the permeability of the cellular membrane affect the distribution of the antibiotic between medium and mycelium.