EFFECTS OF SALINOMYCIN AND VITAMIN-B-6 ON IN-VITRO METABOLISM OF PHENYLALANINE AND ITS RELATED-COMPOUNDS BY RUMINAL BACTERIA, PROTOZOA AND THEIR MIXTURE

Authors
Citation
Mr. Amin et R. Onodera, EFFECTS OF SALINOMYCIN AND VITAMIN-B-6 ON IN-VITRO METABOLISM OF PHENYLALANINE AND ITS RELATED-COMPOUNDS BY RUMINAL BACTERIA, PROTOZOA AND THEIR MIXTURE, Journal of General and Applied Microbiology, 44(1), 1998, pp. 1-9
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology,"Biothechnology & Applied Migrobiology
ISSN journal
0022-1260
Volume
44
Issue
1
Year of publication
1998
Pages
1 - 9
Database
ISI
SICI code
0022-1260(1998)44:1<1:EOSAVO>2.0.ZU;2-4
Abstract
An in vitro study was conducted to examine the effects of salinomycin (SL) and vitamin B-6 (B-6) on the production of phenylalanine (Phe) fr om phenylpyruvic acid (PPY) and phenylacetic acid (PAA) and of PAA fro m Phe and PPY by mixed rumen bacteria (B), mixed rumen protozoa (P) an d their mixture (BP). Rumen microorganisms were collected from fistula ted goats fed lucerne cubes (Medicago sativa) and a concentrate mixtur e (3:1) twice a day. Microbial suspensions were anaerobically incubate d at 39 degrees C for 12 h. Phe and some other related compounds in bo th supernatants and microbial hydrolysates of the incubations were ana lyzed by HPLC. When PPY was used as a substrate, it completely disappe ared without additives and converted mainly to Phe and PAA on the aver age by 396 and 178, 440 and 189, and 439 and 147 mu M in B, P and BP, respectively, during the 12 h incubation period. The rate of disappear ance showed no significant differences between the microbial suspensio ns with and without SL and B-6 during the incubation period. The produ ction of Phe from PPY with SL was enhanced (p<0.05) by 40, 20 and 19% in B, P and BP, respectively, while PAA production from PPY with SL wa s inhibited (p<0.05) by 35, 37 and 38% in B, P and BP, respectively, d uring the 12 h incubation period. On the other hand, with B-6, the pro duction of Phe and PAA from PPY tended to be enhanced by 14 and 17, 9 and 11, and 7 and 22% in B, P and BP, respectively, during the 12 h in cubation period. When PAA added as a substrate was incubated in the in cubation medium without any additives, it disappeared by 483, 462 and 507 mu M and converted mainly to Phe on the average by 231, 244 and 24 8 mu M in B, P and BP, respectively. The disappearance of PAA with SL was inhibited (p<0.05) by 16, 15 and 20%, in B, P and BP, respectively , whereas the disappearance of PAA with B-6 was almost the same as tha t without B-6 in B and BP suspensions but tended to be enhanced by mor e than 9% in P suspensions during the 12 h incubation period. The prod uction of Phe from PAA with SL tended to be inhibited by 12, 11 and 8% in B, P and BP, respectively, during the 6 h incubation period, but t he inhibition was weakened during the 12 h incubation period, whereas Phe production from PAA with B-6 tended to be enhanced by 13, 16 and 8 % in B, P and BP, respectively. When Phe was added as a substrate, the net Phe disappearance without additives was 549, 365 and 842 mu M and converted mainly to PAA on the average by 254, 205 and 461 mu M in B, P and BP, respectively. The net disappearance of Phe with SL was inhi bited (p<0.05) by 38, 28 and 46%, whereas the net disappearance of Phe with B-6 was enhanced (p<0.05) by 9, 8 and 7% in B, P and BP, respect ively. The production of PAA from Phe with SL was inhibited (p<0.05) b y 73, 54 and 76% in B, P and BP, respectively. On the other hand, with B-6, PAA production from Phe was enhanced (p<0.05) by 19, 18 and 20% in B, P and BP, respectively. Based on these results, it seems that SL inhibited Phe disappearance and enhanced the synthesis of Phe from PP Y, though not from PAA, and accumulated free Phe in the medium, wherea s B-6, also enhanced Phe synthesis both from PPY and PAA, which could provide additional amino N for animals.