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A bacteriocin Produced by Pediococcus sp. NPIB-38 isolated from rice Koji
J. BIOSCI.BIOENG.,
Abstracts of the Articles Printed in Seibutsu-kogaku
Kaishi
Vol. 80, Nos. 5 & 6 (2002) Ultra-High-Density Culture of the Rotifer Brachionous rotundiformis Using a Membrane Filtration Unit and Its Effect on Bacterial Abundance in the Rotifer Body. KENJI TANAKA,‘* NORIHIRO TAKEDA,’ YUJI MINAMI,’ MASAKI KURAMOTO,’ KENJI YOSHIMURA,~ and TAKAOYOSHIMATSU~ (Department of Biological and Environmental Chemistq Kyushu School of Engineering, Kinki Universiv, Iizuka, Fukuoka 82045.55, ’Fukuoka Mariculture Corp., Genkai, Munakata, Fukuoka 811-3~712,~and Laboratoory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Hakozaki, Fukuoka 812~85813) Seibutsu-kogaku 80: 181-187. 2002. We have developed a novel culture system designed for ultrahigh-density production of the so-called S-type marine rotifer (Brachionus rotundiformis), which has become an indispensable initial food item for larval cultures of marine fishes and crustaceans. In our culture system, a membrane-type micro-filtration unit (pore size was 0.4 pm) was incorporated in a culture tank (40 r) to prevent accumulation of NH,‘, which is a strong inhibitor of rotifer growth. In rotifer batch culture tests with and without the culture system, freshwater Chlorella paste (Chlorella regularis; packed vol., 600 ml/l) was fed continuously into the culture water using a peristaltic tube pump at feed rates from 3.8-8.0 l/tank/d. Oxygen gas (purity, 90%) was fed at a rate of 0.2 vvm. In the batch culture system with the filtration unit, the culture broth was filtered out through the unit and fresh seawater was supplied to maintain the culture volume in the tank. In batch culture without filtration, the rotifer density reached 40,000 rotifers/ml after 2 d. However, the rotifer density subsequently seriously decreased due to an increase in the NH,’ concentration up to 900 ppm. In contrast, in the culture with filtration the NH,+ concentration remained below 240 ppm after 4d, and as a result the rotifer density reached 160,000 ind./ml. The population of Vibrio sp. in the rotifer body diminished from 1O9to 1O3CFU/g-rotifer as a consequence of using the filtration unit.
A Bacteriocin Produced by Pediococcws sp. NPIB-38 Isolated from Rice Koji. -NoteMITSUOIU KANEOKE,* KEN-ICHI WATANABE, TOSHIO AOKI, YOSHIHITONABEKURA, KEIGO SATO, and MOTOTSUGUTSWIOKA (Niigata Prefectural Institute of Brewing, Suido-cho 2, Niigata 9518121) Seibutsu-kogaku 80: 223-226. 2002. Pediococcus sp. NPIB-38, isolated from a rice koji, produced an antibacterial substance active against selected strains of LactobaciNus spp. The substance was partially purified and then tested for its stability to heating, organic solvents, various pH values, and proteolytic enzymes. The substance was bactericidal against sensitive indicators, and sensitive to proteolytic enzymes; it was indentified as a bacteriotin. The bacteriocin was stable from pH 2.0-10.0 and the antimicrobial activity remained even after autoclaving at 12 1‘C for 10 min. * Corresponding author.
* Corresponding author.
622
Abstracts of the Articles Printed in Seibutsu-kogaku
Kaishi
Vol. 80, Nos. 5 & 6 (2002) Ultra-High-Density Culture of the Rotifer Brachionous rotundiformis Using a Membrane Filtration Unit and Its Effect on Bacterial Abundance in the Rotifer Body. KENJI TANAKA,‘* NORIHIRO TAKEDA,’ YUJI MINAMI,’ MASAKI KURAMOTO,’ KENJI YOSHIMURA,~ and TAKAOYOSHIMATSU~ (Department of Biological and Environmental Chemistq Kyushu School of Engineering, Kinki Universiv, Iizuka, Fukuoka 82045.55, ’Fukuoka Mariculture Corp., Genkai, Munakata, Fukuoka 811-3~712,~and Laboratoory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Hakozaki, Fukuoka 812~85813) Seibutsu-kogaku 80: 181-187. 2002. We have developed a novel culture system designed for ultrahigh-density production of the so-called S-type marine rotifer (Brachionus rotundiformis), which has become an indispensable initial food item for larval cultures of marine fishes and crustaceans. In our culture system, a membrane-type micro-filtration unit (pore size was 0.4 pm) was incorporated in a culture tank (40 r) to prevent accumulation of NH,‘, which is a strong inhibitor of rotifer growth. In rotifer batch culture tests with and without the culture system, freshwater Chlorella paste (Chlorella regularis; packed vol., 600 ml/l) was fed continuously into the culture water using a peristaltic tube pump at feed rates from 3.8-8.0 l/tank/d. Oxygen gas (purity, 90%) was fed at a rate of 0.2 vvm. In the batch culture system with the filtration unit, the culture broth was filtered out through the unit and fresh seawater was supplied to maintain the culture volume in the tank. In batch culture without filtration, the rotifer density reached 40,000 rotifers/ml after 2 d. However, the rotifer density subsequently seriously decreased due to an increase in the NH,’ concentration up to 900 ppm. In contrast, in the culture with filtration the NH,+ concentration remained below 240 ppm after 4d, and as a result the rotifer density reached 160,000 ind./ml. The population of Vibrio sp. in the rotifer body diminished from 1O9to 1O3CFU/g-rotifer as a consequence of using the filtration unit.
A Bacteriocin Produced by Pediococcws sp. NPIB-38 Isolated from Rice Koji. -NoteMITSUOIU KANEOKE,* KEN-ICHI WATANABE, TOSHIO AOKI, YOSHIHITONABEKURA, KEIGO SATO, and MOTOTSUGUTSWIOKA (Niigata Prefectural Institute of Brewing, Suido-cho 2, Niigata 9518121) Seibutsu-kogaku 80: 223-226. 2002. Pediococcus sp. NPIB-38, isolated from a rice koji, produced an antibacterial substance active against selected strains of LactobaciNus spp. The substance was partially purified and then tested for its stability to heating, organic solvents, various pH values, and proteolytic enzymes. The substance was bactericidal against sensitive indicators, and sensitive to proteolytic enzymes; it was indentified as a bacteriotin. The bacteriocin was stable from pH 2.0-10.0 and the antimicrobial activity remained even after autoclaving at 12 1‘C for 10 min. * Corresponding author.
* Corresponding author.
622