scholarly journals Effects of a Probiotic Bacterium, Lactobacillus acidophilus, on the Growth and Survival of Pearl Oyster (Pinctada margaritifera) Spat

2007 ◽  
Author(s):  
A.P. Lipton ◽  
S.K. Subhash
Keyword(s):  
Lactobacillus Acidophilus ◽  
Pearl Oyster ◽  
Probiotic Bacterium ◽  
Pinctada Margaritifera ◽  
Growth And Survival

Nutritional Value of Binary Microalgal Diets for Larvae of the Blacklip Pearl Oyster Pinctada margaritifera (L.)

2007 ◽  
Vol 20 (1) ◽  
Author(s):  
I. TEAIORO ◽  
I. ARABUA ◽  
J. WHITFORD ◽  
P.C. SOUTHGATE
Keyword(s):  
Nutritional Value ◽  
Pearl Oyster ◽  
Individual Species ◽  
Pacific Region ◽  
Chaetoceros Muelleri ◽  
Pinctada Margaritifera ◽  
Growth And Survival ◽  
Culture Techniques ◽  
The Mean ◽  
The Individual

This paper reports on two experiments to assess the nutritional value of cultured microalgae for larvae of the blacklip pearl oyster, Pinctada margaritifera. In the first experiment, two binary diets were assessed and Isochrysis sp. (T-ISO) was administered in combination with either Pavlova salina or the diatom Chaetoceros muelleri. The second experiment assessed the nutritional value of the individual species of microalgae from the best binary diet used in the first experiment (T-ISO and C. muelleri). Larvae fed T-ISO/C. muelleri in the first experiment showed significantly better growth and survival (P < 0.05) than those fed T-ISO/Pav. salina after 20 days of feeding. Administering the microalgae from the best binary diet separately, showed that C. muelleri alone is unsuitable for rearing D-stage P. margaritifera larvae. Larvae fed with T-ISO showed significantly better growth and survival (P < 0.05) than those fed C. muelleri at the end of 9 days of feeding and the slower growth rate of larvae fed C. muelleri was apparent from day 5. The mean antero-posterior shell measurement (APM) of larvae fed C. muelleri at day 5 (88.33 ± 1.95 μm) was significantly smaller (P < 0.05) than that of the larvae fed T-ISO (94.33 ± 4.47 μm). The data generated in this study will be valuable in the further refinement of hatchery culture techniques for P. margaritifera throughout the Indo-Pacific region.

scholarly journals Microarray Analysis of a Two-Component Regulatory System Involved in Acid Resistance and Proteolytic Activity in Lactobacillus acidophilus

2005 ◽  
Vol 71 (10) ◽  
pp. 5794-5804 ◽  
Author(s):  
M. Andrea Azcarate-Peril ◽  
Olivia McAuliffe ◽  
Eric Altermann ◽  
Sonja Lick ◽  
W. Michael Russell ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Proteolytic Activity ◽  
Lactobacillus Acidophilus ◽  
Regulatory System ◽  
Probiotic Bacterium ◽  
Transport Systems ◽  
Logarithmic Phase ◽  
Histidine Protein Kinase ◽  
Regulatory Systems ◽  
Two Component

ABSTRACT Two-component regulatory systems are one primary mechanism for environmental sensing and signal transduction. Annotation of the complete genome sequence of the probiotic bacterium Lactobacillus acidophilus NCFM revealed nine two-component regulatory systems. In this study, the histidine protein kinase of a two-component regulatory system (LBA1524HPK-LBA1525RR), similar to the acid-related system lisRK from Listeria monocytogenes (P. D. Cotter et al., J. Bacteriol. 181:6840-6843, 1999), was insertionally inactivated. A whole-genome microarray containing 97.4% of the annotated genes of L. acidophilus was used to compare genome-wide patterns of transcription at various pHs between the control and the histidine protein kinase mutant. The expression pattern of approximately 80 genes was affected by the LBA1524HPK mutation. Putative LBA1525RR target loci included two oligopeptide-transport systems present in the L. acidophilus genome, other components of the proteolytic system, and a LuxS homolog, suspected of participating in synthesis of the AI-2 signaling compound. The mutant exhibited lower tolerance to acid and ethanol in logarithmic-phase cells and poor acidification rates in milk. Supplementation of milk with Casamino Acids essentially restored the acid-producing ability of the mutant, providing additional evidence for a role of this two component system in regulating proteolytic activity in L. acidophilus.

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