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Growth inhibition of resting Escherichia coli B cells after pre-incubation in a phosphate buffer exposed to an alternating current
Abstracts of the Articles Printed in Hakkokogaku Kaishi
469
Abstracts of the Articles Printed in Hakkokogaku Kaishi g o 1 . 64, N o . 5 (1986)
Effects o f V a r i o u s Concentrations a n d R a t i o s o f protective effect on the decrease in v of the cells. Ion chromatography and U V spectrophotometry Nitrogen and P h o s p h o r u s on the G r o w t h o f revealed some interesting differences between the ChloreUa pyrenoidosa. MAsAo KONDO and HARUHISA OGITA (Aichi Environmental Research components of the buffer exposed and unexposed to Center, 7-6, Nagare, Tsuji-machi, Kita-ku, Nagoya AC: pyrophosphate, a kind of condensed phosphate, 462, Japan) Hakkokogaku 64: 401~06. 1986. was detected in the exposed buffer but not in the Batch cultures of Chlorella pyrenoidosa were grown unexposed buffer, and the concentration of orthophosfor various concentrations and ratios of nitrogen (N) phate decreased and that of hypophosphite increased and phosphorus (P). At the same nitrogen concen- with increasing AC-exposure time. tration, the growth increased as the phosphorus concentration was higher and the N/P ratio was lower. G r o w t h Inhibition o f Lactic a c i d Bacteria b y The cellular N/P ratio varied widely by the algal S a m a c (lffaeharanffa flrandifolia Lima.) Bark. luxurious uptake of phosphorus. The algae could use KIYOSHI MURA, YOJI IITOI, and WAHACHIRO various compounds of nitrogen, but its preference for TAmMURA (Department of Nutrition, Faculty oc nitrogenous compounds varied on the experimental Agriculture, Tokyo University of Agriculture, 1-1-1 conditions. Phosphate-phosphorus was used preferSakuragaoka, Setagaya-ku, Tokyo 156, Japan) entially to dissolved organic phosphorus, when the Hakkokogaku 64: 417-423. 1986. concentration of phosphorus was less than 1 mg/l. We studied the growth inhibition of lactic acid However, when the concentration was more than bacteria by samac bark added to basi (Philippine 10 rag/l, the preference was reversed. Nitrogen and sugarcane wine). phosphorus were removed most efficiently (over 95%) 1. It was found that the inhibitory substance for the at concentrations of 1 mg/l for nitrogen and 0.1 mg/l growth of lactic acid bacteria is the polyphenol comfor phosphorus. ponent, since the growth of lactic acid bacteria was not inhibited by the aqueous extract of samac bark after G r o w t h Inhibition o f R e s t i n g Eseherichia coli B removal of the polyphenol component by precipitation Cells after Pre-Incubation in a P h o s p h a t e Buffer with gelatin. We suspect that the combination of E x p o s e d to an A l t e r n a t i n g C u r r e n t . KEmo polyphenols with protein might inhibit the bacteria. SHIMADA and KENZO SHIMAHARA (Department of 2. Both outer and inner solutions after dialysis Industrial Chemistry, Faculty of Engineering, Seikei inhibited the growth of lactic acid bacteria, but the University, Kichijoji-Kitamachi, Musashino-shi, Tokyo growth inhibition by the inner solution was greater 180, Japan) Hakkokogaku 64: 407-415. 1986. than the outer solution, and most polyphenol comGrowth of resting Escherichia coli B cells was ponents remained in the inner solution. Therefore, inhibited after pre-incubation of the cells in a 8/15 M we suspected that the polyphenol component of phosphate buffer, pH 7.0, anaerobically exposed to an polymers greatly inhibit the growth of lactic acid alternating current (AC) of 50 Hz at a current density bacteria. of 600 mA/cm~ and 34±3°C. The growth inhibition 3. Lactic acid bacteria grown in a medium with the of the cells pre-incubated in the AC-exposed buffer aqueous extract of samac bark were aggregated, and could be evaluated by the method of growth delay the surfaces of the cells were covered with granular analysis, and the integrated viability (v) of the cells matter. decreased with increasing time or temperature during 4. The fact that oxidation-reduction potential of pre-incubation. The decrease in v of the cells was aqueous suspensions of lactic acid bacteria were lowered suppressed when cells were pre-incubated in the when the cell surface was covered with adhered matter exposed buffer after the treatment of the buffer with suggests that the adhered matter is polyphenols which adsorbents, such as activated charcoal powder or an act as reductant, and adhesion of polyphenol comanion exchange resin, or with heat at 121°C. ponents to the cell surface is presumed to be related to Addition of cysteine in the exposed buffer had a the growth inhibition of lactic acid bacteria.
469
Abstracts of the Articles Printed in Hakkokogaku Kaishi g o 1 . 64, N o . 5 (1986)
Effects o f V a r i o u s Concentrations a n d R a t i o s o f protective effect on the decrease in v of the cells. Ion chromatography and U V spectrophotometry Nitrogen and P h o s p h o r u s on the G r o w t h o f revealed some interesting differences between the ChloreUa pyrenoidosa. MAsAo KONDO and HARUHISA OGITA (Aichi Environmental Research components of the buffer exposed and unexposed to Center, 7-6, Nagare, Tsuji-machi, Kita-ku, Nagoya AC: pyrophosphate, a kind of condensed phosphate, 462, Japan) Hakkokogaku 64: 401~06. 1986. was detected in the exposed buffer but not in the Batch cultures of Chlorella pyrenoidosa were grown unexposed buffer, and the concentration of orthophosfor various concentrations and ratios of nitrogen (N) phate decreased and that of hypophosphite increased and phosphorus (P). At the same nitrogen concen- with increasing AC-exposure time. tration, the growth increased as the phosphorus concentration was higher and the N/P ratio was lower. G r o w t h Inhibition o f Lactic a c i d Bacteria b y The cellular N/P ratio varied widely by the algal S a m a c (lffaeharanffa flrandifolia Lima.) Bark. luxurious uptake of phosphorus. The algae could use KIYOSHI MURA, YOJI IITOI, and WAHACHIRO various compounds of nitrogen, but its preference for TAmMURA (Department of Nutrition, Faculty oc nitrogenous compounds varied on the experimental Agriculture, Tokyo University of Agriculture, 1-1-1 conditions. Phosphate-phosphorus was used preferSakuragaoka, Setagaya-ku, Tokyo 156, Japan) entially to dissolved organic phosphorus, when the Hakkokogaku 64: 417-423. 1986. concentration of phosphorus was less than 1 mg/l. We studied the growth inhibition of lactic acid However, when the concentration was more than bacteria by samac bark added to basi (Philippine 10 rag/l, the preference was reversed. Nitrogen and sugarcane wine). phosphorus were removed most efficiently (over 95%) 1. It was found that the inhibitory substance for the at concentrations of 1 mg/l for nitrogen and 0.1 mg/l growth of lactic acid bacteria is the polyphenol comfor phosphorus. ponent, since the growth of lactic acid bacteria was not inhibited by the aqueous extract of samac bark after G r o w t h Inhibition o f R e s t i n g Eseherichia coli B removal of the polyphenol component by precipitation Cells after Pre-Incubation in a P h o s p h a t e Buffer with gelatin. We suspect that the combination of E x p o s e d to an A l t e r n a t i n g C u r r e n t . KEmo polyphenols with protein might inhibit the bacteria. SHIMADA and KENZO SHIMAHARA (Department of 2. Both outer and inner solutions after dialysis Industrial Chemistry, Faculty of Engineering, Seikei inhibited the growth of lactic acid bacteria, but the University, Kichijoji-Kitamachi, Musashino-shi, Tokyo growth inhibition by the inner solution was greater 180, Japan) Hakkokogaku 64: 407-415. 1986. than the outer solution, and most polyphenol comGrowth of resting Escherichia coli B cells was ponents remained in the inner solution. Therefore, inhibited after pre-incubation of the cells in a 8/15 M we suspected that the polyphenol component of phosphate buffer, pH 7.0, anaerobically exposed to an polymers greatly inhibit the growth of lactic acid alternating current (AC) of 50 Hz at a current density bacteria. of 600 mA/cm~ and 34±3°C. The growth inhibition 3. Lactic acid bacteria grown in a medium with the of the cells pre-incubated in the AC-exposed buffer aqueous extract of samac bark were aggregated, and could be evaluated by the method of growth delay the surfaces of the cells were covered with granular analysis, and the integrated viability (v) of the cells matter. decreased with increasing time or temperature during 4. The fact that oxidation-reduction potential of pre-incubation. The decrease in v of the cells was aqueous suspensions of lactic acid bacteria were lowered suppressed when cells were pre-incubated in the when the cell surface was covered with adhered matter exposed buffer after the treatment of the buffer with suggests that the adhered matter is polyphenols which adsorbents, such as activated charcoal powder or an act as reductant, and adhesion of polyphenol comanion exchange resin, or with heat at 121°C. ponents to the cell surface is presumed to be related to Addition of cysteine in the exposed buffer had a the growth inhibition of lactic acid bacteria.