Distribution of the Luminous Bacterium Beneckea harveyi in a Semitropical Estuarine Environment

Abstract

Bioluminescent bacteria were found in the water column, sediment, shrimp, and gastrointestinal tract of marine fishes from the semitropical estuarine environment of the East Lagoon, Galveston Island, Tex. Populations in the water column decreased during cold weather while sedimentary populations persisted. The highest percentages of luminous organisms were isolated from the gastrointestinal tract of marine fishes, where they persisted during 5 days of starvation. The presence of chitin temporarily increased intestinal populations. All isolates were Beneckea harveyi, whose natural habitat appears to be the gut of fishes and whose free-living reservoir appears to be marine sediments. Luminescent bacteria are found saprophytically and parasitically on marine animals and live symbiotically in specialized organs in certain marine fish and cephalopods (2). Although the biochemistry, physiology and, most recently, the from the East Lagoon for 12 months (June 1977 to June 1978). Water samples were collected in sterilized milk dilution bottles, capped, and returned to the laboratory within 1 h for processing. Sediment samples were collected in a polypropylene centrifuge tube with a hole drilled in the bottom. The 928

Luminous microflora associated with the fishes Mugil cephalus and Tachysurus arius

“…The negative relationship encountered suggested that the size of luminous microflora did not depend on the weight of the food alone. The findings of the present study are in contrast to those of Ruby and Morin [6] and O'Brien and Sizemore [7] who reported a relationship between the bacterial population and the feeding intensity of fish. It is also possible that the population size of the luminous microflora depends on the relative weight of various items in the diet rather than on the absolute weight of the food.…”

“…Minimum counts were recorded when crustaceans were present in lesser proportions in the diet. Our observations concurred with those of O'Brien and Sizemore [7] who proved experimentally that fish fed with chitin-supplemented food registered greater counts of luminous bacteria than fish fed with food lacking chitin. Hence, the crustacean diet may account for the relative abundance of luminous bacteria in the gut of T. arius compared to that in M. cephalus.…”

“…This was followed by V. fischeri. Preponderance of V. haroeyi in the gut was reported by Nair et al [21], O'Brien and Sizemore [7] and Ramesh et al [22]. The main rationale for the distribution of V. harveyi might be its nutritional versatility [19] as it is able to utilize between 30 and 45 organic compounds (depending upon the strain).…”

“…The extent of distribution of luminous bacteria among the total bacterial population (CFU) is quite interesting, 18-54% of the bacterial colonies isolated from the gut of Argyropelecus hemigymnus, Oxyjulis californica and Chromis punctipinnis being photogenic [6]. O'Brien and Sizemore [7] found that 0.44 and 20.55% of the total viable counts from stomach and intestine, respectively, were luminous. On the whole, the findings of the present investigation revealed that the luminous 31 microbiota (harboured in skin, gill and gut) constitute a significant portion of the total heterotrophic bacterial population with the luminous counts at times reaching up to 84% of the total counts.…”

Characterization and virulence retention of viable but nonculturable Vibrio harveyi

“…Vibrio harveyi is a Gram-negative, luminous, marine bacterium occurring either free living or in association with marine forms of life such as fish and crustaceans (O'Brien & Sizemore, 1979;Orndorff & Colwell, 1980;Ramesh & Venugopalan, 1989). The organism has been reported as a major causal agent of luminous vibriosis, which affects a diverse range of marine invertebrates.…”