Growth performance of Chlorella ellipsoidea as biomicrocapsule using supernatant of digested sugar mill waste effluent

Biomicrocapsules mean microscopic living organisms which carry important nutrients, very essential for the growth and development of aquatic organisms as well as other animals. Among these biomicrocapsules, Chlorella ellipsoidea, an important green microalga (Chlorophyceae) which contains 40-45% crude protein, 12-16% crude lipid, 14-15% minerals, colour pigments, vitamins and carotene. The microalga, C. ellipsoidea was cultured in four different dilutions of supernatant of digested sugar mill effluent (DSME) i.e. 25, 50, 75 and 100% DSME and Bold basal medium (BBM) as control in laboratory condition. Maximum cell growth and chlorophyll a content of C. ellipsoidea were obtained on l0th day of culture in supernatant of 50% diluted DSME followed by those of this biomicrocapsule grown in BBM, and 75, 25 and 100% DSME at stationary phase. Cell number had highly (p<0.01) direct correlation with chlorophyll a (r = 0.889) of C. ellipsoidea, and optical density (r = 0.926) of media. Chlorophyll a was also highly (p<0.01) and directly correlated with optical density (r= 0.877) of media. The specific growth rates (µ/day) of cell and chlorophyll a of C. ellipsoidea grown in supernatant of 50% DSME were significantly (p<0.01) varied from those of C. ellipsoidea cultured in BBM followed by other DSME. Total biomass of C. ellipsoidea cultured in supernatant of 50% DSME was found significantly (p<0.01) higher than that of this microalga cultured in BBM, and supernatant of 25, 75 and 100% DSME. Similar trend was also observed in the case of optical density. The physico-chemical properties of media were varied with the growth of cell of this microalga. It was recorded that cell number, chlorophyll a of biomicrocapsule, and optical density of media were highly (p<0.01) and directly correlated with pH, hardness and alkalinity, and inversely correlated with nitrate-N. Crude protein and crude lipid of C. ellipsoidea grown in supernatant of 50% DSME were significantly (p<0.01) higher than those of C. ellipsoidea cultured in other DSME and BBM. Due to best growth performance exhibited by this microalga grown in supernatant of 50% DSME, it may be used to grow in supernatant of 50% DSME to get more essential nutrients than that cultured in supernatant of other DSME media.

Water soluble nitrogenous component from squilla (Orato squilla nepa)

A water soluble hygroscopic powder has been isolated from squilla in good yield, ranging from 3.5 to 5.0% of the fresh raw material, by a simple direct method. The process consists of homogenising squilla with an equal quantity of water, removal of chitinous matter from the slurry by filtration, heating the filtrate at 0.7 kg/sq.cm steam pressure for 15-20 minutes, removal of the precipitated protein by filtration and concentration and final drying in vacuum of the filtered cooled liquor. The pale brown powder so obtained consists mainly of peptones and proteoses and has been found to be comparable to BDH peptone for growth of bacteria, ability to serve as source for tryptophan for indole production and to provide substrate for the production of hydrogen sulphide. Comparative studies have been made on similar water soluble fractions from two species of prawns, namely, Metapenaeus affinis and Parapenaeopsis stylifera.

Soluble protein isolated from low cost fish and fish wastes

The method of preparation, composition, amino acid content, protein efficiency ratio and areas of possible application of water soluble protein isolates from low cost fish and fish wastes are discussed in detail in this communication.

Study of physicochemical, microbial and sensory properties of surimi produced from black mouth croaker (Atrobucca nibe) at freezing condition (-18ºC)

Black mouth croaker (Atrobucca nibe) is considered as a new valuable fish stock in the Oman Sea. In this study, surimi was manufactured from nonmarket size of the fish, manually and different cryoprotectant agents were added to the surimi. Finally changes in physiochemical, microbiological and sensory quality, characteristics of the surimi and kamaboko gel samples were assessed during 6 months at freezing storage (-18ºC). Surimi samples with the addition of Iranian tragacanth gum (TG), xanthan gum (XG), chitosan (CS) and whey protein concentrate (WPC) at 1% (w/w) were prepared to evaluate their impacts as a cryoprotectant on the surimi, individually. The results showed that the whiteness and lightness indexes in all surimi samples were gradually decreased during frozen storage. This trend of decreasing was more intensity in the control sample from 61.08±0.131 to 54.21±0.067 was recorded (p<0.05). Water holding capacity (WHC) in all treatments was decreased during 6 months. The lowest WHC (g/g) was obtained in the surimi without cryoprotectants and maximum WHC was measured in Tcs and Twpc samples, respectively (p<0.05). The lowest breaking force was calculated in Txg (166.00±22.627 g) and Tc (271.50±263.16 g) during 6 months at frozen storage, respectively (p<0.05), while Twpc treatment with slight variations showed the highest breaking force (p<0.05). Also, the lowest gel strength was obtained in Txg (68.22±6.740 g.cm) after 6 month of frozen storage (p<0.05). All Kamaboko surimi gels texture profile analysis parameters decreaced with increasing shelf life. This decreasing trend in the control sample was more severe. Floding results were reduced in all samples during storage (p<0.05). The best protective results probably were obtained in WPC, chitosan and commercial cryoprotectant agents, respectively due to protein stabilization of myofibrillar proteins and the protein-protein network structure, leading to the formation of surimi gel with strong textural properties during frozen conditions. The average number of surimi polygonal structures were significantly decreased (number per mm2) and their area were significantly increased (μm2) in all treatments (p<0.05). With increasing storage time, moisture, protein contents and pH were decreaced. Maximun TVB-N index was calculated in Tc (7.93±0.400 mg/100g) and Txg (7.88±0.477), respectively (p<0.05). TBRAs index was increased in all treatments during frozen storage, while this trend was reached in maximum value in Tc (p<0.05). Sensory evaluation of the fish finger quality characteristics (color, odor, texture and overall acceptability) preapare from frozen black mouth croaker surimi was decreaced during 6 month frozen storage. After the period of frozen storage the highest quality scores were measured in Twpc, Tcs and Tcc samples, respectively (p<0.05). In this study, coliform bacteria were not found in all treatments during frozen storage. The surimi sample containing chitosan showed lower mesophilic and psychrotropic bacteria (log cfu/g) than other treatments during frozen storage (p<0.05). Salt-soluble proteins extractions of all treatments were decreased during frozen storage. This decreacing trend was highest in Tcs (45.74±0.176%) and lowest in Tc treatments after 6 month of frozen storage (29.92±0.224%) (p<0.05). Although commercial cryoprotectant agents were successful in limiting the denaturation of proteins but sugar contents were not accepted for diabetics or those who disagree with the sweet taste and high calorie food. Hence, commercial cryoprotectant agents can be replaced with whey protein concentrate and chitosan at 1% level (w/w) consider that they were showed proper protection of the surimi myofibrillar proteins during storage.

Effect of sugar type on the survival of frozen-thawed rhesus monkey (Macaca mulatta) sperm

Sperm-freezing extenders supplemented with sugar or a combination of different sugars are widely used for the cryopreservation of nonhuman primate spermatozoa. Understanding which sugar or combination of sugars offers the highest level of cryoprotection w

Soft-lithographic processed soluble micropatterns of reduced graphene oxide for wafer-scale thin film transistors and gas sensors

PDMS based imprinting is firstly developed for patterning of rGO on a large area. High quality stripe and square shaped rGO patterns are obtained and the electrical properties of the rGO film can be adjusted by the concentration of GO suspension. The arrays of rGO electronics are fabricated from the patterned film by a simple shadow mask method. Gas sensors, which are based on these rGO electronics, show high sensitivity and recyclable usage in sensing NH 3. © 2012 The Royal Society of Chemistry.

Trends of Superoxide Dismutase and Soluble Protein of Aquatic Plants in Lakes of Different Trophic Levels in the Middle and Lower Reaches of the Yangtze River, China

A limnological study was carried out to determine the responses of superoxide dismutase (SOD) activities and soluble protein (SP) contents of 11 common aquatic plants to eutrophication stress. Field investigation in 12 lakes in the middle and lower reaches of the Yangtze River was carried out from March to September 2004. Our results indicated that non-submersed (emergent and floating-leafed) plants and submersed plants showed different responses to eutrophication stress. Both SOD activities of the non-submersed and submersed plants were negatively correlated with their SP contents (P < 0.000 1). SP contents of non-submersed plants were significantly correlated with all nitrogen variables in the water (P < 0.05), whereas SP contents of submersed plants were only significantly correlated with carbon variables as well as ammonium and Secchi depth (SD) in water (P < 0.05). Only SOD activities of submersed plants were decreased with decline of SD in water (P < 0.001). Our results indicate that the decline of SOD activities of submersed plants were mainly caused by light limitation, this showed a coincidence with the decline of macrophytes in eutrophic lakes, which might imply that the antioxidant system of the submersed plants were impaired under eutrophication stress.

Relationships among the contents of total phenolics, soluble carbohydrate, and free amino acids of 15 aquatic macrophytes

In order to examine how carbon and nitrogen status of a macrophyte may affect its total phenolics (TP) production, the contents of free amino acids (FAA), soluble carbohydrate (SC) and TP were examined in leaves of seven submersed, four floating-leaved, and four emergent macrophytes. The floating-leaved and emergent macrophytes had much higher contents of SC and TP than the submersed macrophytes. The contents of FAA were not significantly different among the submersed, floating-leaved, and emergent macrophytes. Correlations among the contents of FAA, SC, and TP indicated that the production of TP was more dependent on the SC content than on the FAA content.

Studies on polysaccharides from three edible species of Nostoc (Cyanobacteria) with different colony morphologies: Comparison of monosaccharide compositions and viscosities of polysaccharides from field colonies and suspension cultures

Hot water-soluble polysaccharides woe extracted from field colonies and suspension cultures of Nostoc commune Vaucher, Nostoc flagelliforme Berkeley et Curtis, and Nostoc sphaeroides Kutzing. Excreted extracellular polymeric substances (EPS) were isolated from the media in which the suspension cultures were grown. The main monosaccharides of the field colony polysaccharides from the three species were glucose, xylose, and galactose, with an approximate ratio of 2:1:1. Mannose was also present, but the levels varied among the species, and arabinose appeared only in N. flagelliforme. The compositions of the cellular polysaccharides and EPS from suspension cultures were more complicated than those of the field samples and varied among the different species. The polysaccharides from the cultures of N. flagelliforme had a relatively simple composition consisting of mannose, galactose, glucose, and glucuronic acid, but no xylose, as was found in the field colony polysaccharides. The polysaccharides from cultures of N. sphaeroides contained glucose (the major component), rhamnose, fucose, xylose, mannose, and galactose. These same sugars were present in the polysaccharides from cultures of N. commune, with xylose as the major component. Combined nitrogen in the media had no qualitative influence on the compositions of the cellular polysaccharides but affected those of the EPS of N. commune and N. flagelliforme. The EPS of N. sphaeroides had a very low fetal carbohydrate content and thus was not considered to be polysaccharide in nature. The field colony polysaccharides could be separated by anion exchange chromatography into neutral and acidic fractions having similar sugar compositions. Preliminary linkage analysis showed that 1) xylose, glucose, and galactose were 1-->4 linked, 2) mannose, galactose, and xylose occurred as terminal residues, and 3) branch points occurred in glucose as 1-->3,4 and 1-->3,6 linkages and in xylose as a 1-->3,4 linkage. The polymer preparations from field colonies had higher kinematic viscosities than those from corresponding suspension cultures. The high viscosities of the polymers suggested that they might DE suitable for industrial uses.