Studies on lipolytic bacteria in stored fish Etroplus suratensis (Bloch)

The distribution of total hectrotrophic bacteria (THB) and lipolytic bacteria in various regions (body surface, gill, intestine and flesh) of fish Etroplus suratensis (Bloch) during storage at 28 ± 2°C and 4°C was studied. Pseudomonas dominated at reduced temperature whereas at 28 ± 2°C and in fresh condition Vibrio, Aeromonas, and Acinetobacter dominated. Lipolytic activity was elaborated by the members of various genera and their activity varied in different lipid compounds (tributyrin, tween 80, tween 60, tween 40 and tween 20). Tributyrin was utilized by majority of the isolates. All the selected isolates preferred a temperature of 35°C and pH 6.0 for their maximum growth. Aeromonas and Vibrio showed maximum growth at 0.5% NaCl concentration while 3% NaCl was found to be optimum for Pseudomonas.

Bacteria from seawater used in Penaeus monodon larval cultures

Bacteria in the seawater used in P. monodon hatchery operations were isolated on Bachmann's agar. The total plate counts in 25 isolations ranged from 1.0 - 5.0 x 10² to 5.1 -10.0 x 10⁵ cells per ml. Out of 124 isolates, 98 (79 percent) were Gram-positive and 26 (21 percent) were Gram-negative. Micrococcus and Staphylococcus were dominant in the former group, while Acinetobacter, Moraxella, Flavobacterium and Alcaligenes were most numerous in the latter. Twenty-nine of the Gram-positive isolates closely resembled Peptostreptococcus, Planococcus, and Pediococcus.

Using bacteria to fight bacteria

The paper discusses about probiotics and its possible use in shrimp aquaculture. The paper also provides information on how the probiotics work and presents the preliminary results of the field tests conducted by Southeast Asian Fisheries Development Center, Aquaculture Department and BIOPOND Systems. The general characteristics of Bacillus are also discussed.

Application of encapsulated nisin and sodium citrate for shelf life increasing of Rainbow trout (Onchorhynchus mykiss) fillet packaged with MAP and their effect on Staphylococcus aureus

Nisin is a widely used naturally occurring antimicrobial effective against many pathogenic and spoilage microorganisms. It has been proposed that reduced efficacy of nisin in foods can be improved by technologies such as encapsulation to protect it from interferences by food matrix components. The aim of this study was using of spray dried encapsulated nisin with zein in concentration of (0.15 and 0.25 g/kg) and sodium citrate (1.5 and 2.5%) and treatments with both of them to extent the shelf life of filleted trouts packaged by Modified Atmosphere Packaging (45% CO2, 50% N2 ,5% O2) and stored at 4±1 °C for 20 days. Furthermore, to evaluate the antimicrobial efficiency of encapsulated nisin and soudium citrate the trouts fillets was inoculated with Staphylococcus aureus as an index pathogenic bacteria. Assessment of chemical spoilage indexes such as (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) , microbial parameters (Total Plate Count, Psychrotrophic count, Lactic acid bacteria count), Staphylococcus aureus cont in treatments which were inoculated with 5 logcfu/g of this bacteria and sensory evaluation of fillets including (smell, color, texture and total acceptability) was carried out in days of 0, 4, 8, 12, 16 and 20. The results revealed that treatment with both exposure of nisin and sodium citrate showed significantly lower chemical spoilage indexes in comparison with controls (vaccum packed and MAP) (P<0.05). Furthermore, (nisin 0.25 g/kg sodium citrate 2.5%) treatment which was exposed to the maximal level used of both materials was significantly the lowest treatment with (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) of 9.95 (meq O2/kg) , 1.55 (mgMA/kg), 29.65 (mgN/100g) and 6.65 , respectively and according to the maximal recommended level of this indices , shelf life of fillets in this treatment was esstimated 20 days.The control (vaccum packed) treatment was significantly the highest treatment with (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) of 15.17 (meq O2/kg), 3.03 (mgMA/kg), 38.4 (mgN/100g) and 6.95 , respectively and according to the maximal recommended level of this indices , shelf life of fillets in this treatment was estimated 11 days. Also, in microbial point of view (nisin 0.25 g/kg- sodium citrate 2.5%) treatment was the lowest treatment with Total Plate Count, Psychrotrophic count, Lactic acid bacteria count and Staphylococcus aureus count of 6.7, 6.83, 5.25 and 6.04 logcfu/g respectively, and conrol (vaccum packed) treatment was the highest treatment with 9.15, 9.41, 7.7 and 9.01 logcfu/g respectively. According to the lower results of chemical and microbial indices and higher sensory evaluated scores assessed in this research for encapsulated nisin in comparison with free nisin , it was concluded that encapsulation of nisin with zein capsules may improve the efficiency of nisin. The measuremented values of Mass yield, Total solids content of capsules, Encapsulation efficiency, In vitro release kinetics in 200 hour for encapsulated nisin in this study was 49.89, 62, 98.31 and 69% respectively and Encapsulated particle size was lower than 674.21 μm for 90% of particles. As a consequence, nisin , in particular encapsulated nisin, and sodium citrate alone or together with and Modified Atmosphere packaging might be considered as effective tools in preventing the quality degradation of the fillets, resulting in an extension of their shelf life.

The study and production of fish sauce from Caspian Sea lam fish with traditional fermentation method and microbe and enzyme adding method and identification of important bacteria

Fish sauce is a popular fermented product used in south Asian countries which is made from different small fishes in this research work it was attempted to produce fish sauce from kilka of the Caspian sea, the fish sauce was made from three models of kilka ,such as whole kilka , cooked whole kilka and dressed kilka , each of these models treated it four different fashions of fermentation such as:1- Traditional method, 2- Enzymatic method 3- Microbial method, 4- Mixture of enzyme and microb The results of this investigation showed that time of fermentation for the traditional method was six month, enzymatic method one month, microbial method 3 month and the mixture of enzyme and microb 1 month. The rate of fermentation was least for dressed Kilka, microbial and biochemical changes of Kilka fish sauce were evaluated, total bacterial count was 2.1-6.15 log cfu/ml total volatile nitrogen (TVN) in samples recorded was 250 mg /100g, the amount of protein varied between 10-13 percent, the name of commercial enzymes added was Protamex and Flavourzyme, the bacteria added was L act ob acillus and Pediococous, fish sauce containers fish and 20% salt, temperature of keeping for fermentation was 37 degree c for 6 month.

Isolatin [sic] the bacteria produced biactive [sic] metabolits [sic] cytotoxic compound in order to prduction [sic] anticancer substance in the coral regin [sic] the Persian Gulf (Larak Island)

In the present investigation the marine bacteria isolated from corals, sponges sea water and sediments of coral regions in the larak Island located in the Persian Gulf and were examined for ability to produce cytotoxic metabolits in order to use as an anticancer compounds. Cytotoxic effect were isolated bacteria from different samples and were examined by Artemia Cytotoxic Bioassay test, in which 4.5 percent of sea waters, 12 percent of sediments and 28 percent of marine invertebrat showed cytotoxic activity, using Brine Shrimp Bioassay test. Streptomyces S-2004 isolated from soft coral specified as Sinularia erecta had LC50=0.5mg/m1 in Brine Shrimp Bioaassay test. The streptomyces S-2004 produced cytotoxic metabolits in low nutrient condition and sea water medium after 7 days on 250 rpm shaken in vitro condition. The extract partially were semipurified. Then ethyl acetate extraction from aceton extracted of bacterial plate had cytotoxic effect (LC50=4.19ktg/m1) in Human epidermoid carcinoma of mouth cells (KB) by using neutral red assay. Morphological effects of this extract on KB cells showed turgescence, cellular blebs and apoptosis which was a proof for anticancer compounds of the extract. It is seems that streptomyces S-2004 is a new strain and could be introduced as a talented bacteria, which produced cytotoxic metabolits.

Isolating and recognizing crudeoiklegrading [sic] bacteria of Queshm Island shores for biodegradation of crude oil pollutions

This research was carried out for recognizing Natural Flora Bacteria of oil pollution in the coasts of Queshm island. In The First steps, The coasts of this Island were scrutinized as a Field of research and For knowing whether oil stains exist or not. It gets obvious That southern coasts of Queshm have got oil pollution which is created by oil tankers which carry oil of Iran continental shelf. Them oil stains were sampled from to certain stations. In The First step, primary isolation of exisiting bacteria in every oil sample was done and then purification of each bacterium was carried out. Then each purified bacterium that has got strong, recognized, typic growth was enriched oil sample of T5 station. And Bacterium C4 (gram—negative coccobacillus) was chosen as the second priority From oil sample of TA station and Bacterium B1 (gram—positive coccus) was chosen as The third priority From oil sample of TI station. All The above mentioned bacteria were biochemically, physiologically and morphologically experimented For specking The species. According To The tests done and comparing with The tests done and comparing with the reference Berge y' s, bacterium A5 Pelongs to the species pseudomonas sp and becterium C4 belongs to the species Aeromonas sp and bacterium BI belongs to The species micrococcus sp. In The Last stage, bacterium with The First priority (TA5 pseudomonas sp) was used in the planned microcosm. The sake of optimum and adapting to Laboratory conditions Each enriched and purified bacterium was given a code for station and a code For itself . Then This bacterium was studied and it was proved that it has potentiality For using oil as a source of carbon. From oil samples of 10 stations, 30 various Colonies of bacterium were Isolated, of which 20 bacteria had the highest potentiality of growth. And the other bacteria that has no typic growth were omitted From being studied. Since all of These 20 bacterium are able to use oil, a bacterium with maximum rate of growth in the presence of crude oil and Lack of other hydrocarbonic sources and with The code A5 ( gram — negative Bacillus ) was chosen as First priority From The mentioned microcosm contains sea water , suspension oil degrading bacterium , crude oil, azote and various concentrations of carbon and Incubated in 30°` and shook 150 PRA1 According to the results , index oil degrading bacterium (pseudomonas sp) belongs oil sample of T5 stations (east of sheeb draz Gulf) which growth best and have the potentiality of degrading oil in 25 glli malas and 50 glli cheese water and with 5 gill urea .