Luminous bacteria

Bacterial cellulose Bacterial leaching Bacterial removal Bacteria, luminous Bactericide... 

Distribution of luminous bacteria. Luminous bacteria are widely distributed in the marine environment, and have been isolated from various sources, including seawater, the light organs and various other parts of marine luminous organisms, sometimes even from nonmarine sources as well. There are several major groups of luminous bacteria... 

Cultivation of luminous bacteria. Nealson (1978) lists various culture media to culture luminous bacteria. Three examples from other sources are shown in Table 2.1. It is important to include 300-500 mM NaCl as a basic ingredient. For the growth of bacteria, liquid media must be adequately aerated by shaking or bubbling. Solid media containing agar are made in Petri dishes. 

Table 2.1 Examples of Culture Media for Growing Luminous Bacteria...

To identify the specific aldehyde that is actually involved in the light-emitting reaction of living luminous bacteria, Shimomura et al. (1974a) extracted and purified the aldehyde from 40 g each of the bacterial cells of P. phosphoreum, Achromobacter (Vibrio or Photobacterium) fischeri, and an aldehydeless mutant of A. fischeri. The aldehyde fractions were purified, and then oxidized with Tollens reagent (silver oxide dissolved in ammonia) to convert the CHO group into the COOH group. Then the acids obtained were analyzed by mass spectrometry. The results indicated that P. phosphoreum had contained a mixture of aldehydes dodecanal (5%), tetradecanal (63%) and hexadecanal (30%), as shown in Table 2.2. Thus, tetradecanal was clearly predominant in... 

Table 2.2 Amounts of Saturated Fatty Aldehyde Extracted from 40 g of Luminous Bacteria (Shimomura et al., 1974a)...

If the luciferase sample solution contains a flavin-reductase, luciferase activity can be measured by the addition of FMN and NADH, instead of FMNH2. In this case, the turnover of luciferase takes place repeatedly using the FMNH2 that is enzymatically generated thus, the luminescence reaction continues until aldehyde or NADH is exhausted. A crude luciferase extracted from luminous bacteria usually contains a flavin-reductase. 

Overview. In the cultures of luminous bacteria, the bacterial cells are not luminous in their early stages of propagation. The formation of bioluminescence system is controlled by a substance called autoinducer that is produced by the cells of luminous bacteria. 

In the living cells of luminous bacteria, FMNH2 is produced by the reduction of FMN with NADH catalyzed by FMN-reductase. This process is, in effect, the recycling of FMN. In the cells, a long-chain aldehyde is produced by the reduction of the corresponding long-chain acid, which is also a recycling process. 

Fig. 2.3 Luminescence spectra of the living cells of luminous bacteria. F, P. fischeri P, P. phosphoreum (Eley etal., 1970) Y, P. fischeri, strain Y-l (Ruby and Nealson, 1977). Reproduced with permission from the American Chemical Society and AAAS.

Two types of fluorescent proteins have been isolated from luminous bacteria and studied in detail. The first of them are the blue fluorescent lumazine proteins (LumPs) containing lumazine as their chromophores, which were isolated from P. phosphoreum and P. fischeri (Gast and Lee, 1978 Koda and Lee, 1979 O Kane et al.y 1985). The second are the yellow fluorescent proteins (YFPs) containing a chromophore of FMN or riboflavin, isolated from P. fischeri strain Y-l (Daubner et al., 1987 Macheroux et ai, 1987 ... 

Heat stability The Oplophorus luminescence system is more thermostable than several other known bioluminescence systems the most stable system presently known is that of Periphylla (Section 4.5). The luminescence of the Oplophorus system is optimum at about 40°C in reference to light intensity (Fig. 3.3.3 Shimomura et al., 1978). The quantum yield of coelenterazine is nearly constant from 0°C to 20°C, decreasing slightly while the temperature is increased up to 50°C (Fig. 3.3.3) at temperatures above 50°C, the inactivation of luciferase becomes too rapid to obtain reliable data of quantum yield. In contrast, in the bioluminescence systems of Cypridina, Latia, Chaetopterus, luminous bacteria and aequorin, the relative quantum yields decrease steeply when the temperature is raised, and become almost zero at a temperature near 40-50°C (Shimomura et al., 1978). 

The New Zealand freshwater limpet Latia neritoides (Fig. 6.1.1) is the only known example of a freshwater luminous organism, with two possible exceptions certain species of luminous bacteria and the larvae of certain species of fireflies. The limpet inhabits shallow clear streams in the North Island of New Zealand, clinging to stones and rocks. Latia has a small oval-shaped shell (6-8 mm long), and secretes a luminous mucus that emits a greenish glow around the body only when disturbed the limpet does not show a spontaneous luminescence. The luminescence of Latia was first reported by Suter (1890) and further details including a positive luciferin-luciferase reaction were described by Bowden (1950). Both the luciferin and the luciferase have... 

There are many kinds of bioluminescent squids. Some of them harbor luminous bacteria for their light emission (Harvey, 1952 Haneda, 1985), but all other luminous squids currently known utilize coelenterazine or its derivatives in their bioluminescence systems, and... 

Low luciferin content. Luminous fungus in various growth stages contains relatively small amounts of luciferin that can sustain the luminescence for a period of only 3-100 s, in resemblance to the situation found in luminous bacteria. In luminous bacteria,... 

The source of light emission. Each individual animal in a colony of Pyrosoma has two groups of luminous cells at the entrance to the branchial sac (Herring, 1978a). The luminous cells contain tubular inclusions whose identity has been a matter of dispute for nearly a century. Buchner (1914) originally suggested that the inclusions were symbiotic luminous bacteria. However, efforts to cultivate luminous bacteria from the luminous cells of Pyrosoma consistently failed. In... 

---