Hayati Journal of Biosciences 

About: Hayati Journal of Biosciences is an academic journal published by Bogor Institute of Agriculture. The journal publishes majorly in the area(s): Biology & Population. It has an ISSN identifier of 1978-3019. It is also open access. Over the lifetime, 745 publications have been published receiving 5467 citations.

Microencapsulation Improved Probiotics Survival During Gastric Transit

Abstract: Several studies have demonstrated differences among strains of probiotic bacteria with regard to their survival in acid environment. Probiotics must survive in gastric acids to reach the small intestine and colonize the host for appropriate prevention and management of several gastrointestinal diseases. To improve the survival rates of probiotic microorganisms during gastric transit, microencapsulation is considered to be a promising process. A variety of polymers are commonly used for microencapsulation. Thus, there is a widespread interest in the improvement of the physical and mechanical stability of the polymers use in probiotics encapsulation. In addition, there is a developing trend toward the use of milk proteins as encapsulation device. To fulfill many demands of a successful probiotics encapsulation, different techniques have been applied to increase the resistance of these sensitive microorganisms against gastric conditions. Therefore, the objective of this study is to review the effect of microencapsulation on survival of probiotics in an in vitro model simulating gastric transit.

Primary Nutritional Content of Bio-Flocs Cultured with Different Organic Carbon Sources and Salinity

Abstract: Application of bio-flocs technology (BFT) in aquaculture offers a solution to avoid environmental impact of high nutrient discharges and to reduce the use of artificial feed. In BFT, excess of nutrients in aquaculture systems are converted into microbial biomass, which can be consumed by the cultured animals as a food source. In this experiment, upconcentrated pond water obtained from the drum filter of a freshwater tilapia farm was used for bio-flocs reactors. Two carbon sources, sugar and glycerol, were used as the first variable, and two different levels of salinity, 0 and 30 ppt, were used as the second variable. Bio-flocs with glycerol as a carbon source had higher total n-6 PUFAs (19.1 + 2.1 and 22.3 + 8.6 mg/g DW at 0 and 30 ppt, respectively) than that of glucose (4.0 + 0.1 and 12.6 + 2.5 mg/g DW at 0 and 30 ppt). However, there was no effect of carbon source or salinity on crude protein, lipid, and total n-3 PUFAs contents of the bio-flocs.

Evaluation of Biofloc Technology Application on Water Quality and Production Performance of Red Tilapia Oreochromis sp. Cultured at Different Stocking Densities

Abstract: This study evaluated the effect of biofloc technology (BFT) application on water quality and production performance of red tilapia Oreochromis sp. at different stocking densities. Three different fish densities were applied, i.e. 25, 50, and 100 fish/m 3 , and for each density there were Control (without external carbon input) and BFT treatments. Mixed sex red tilapia with an initial average body weight 77.89 + 3.71 g was cultured in 3 m 3 concrete tanks for 14 weeks. Molasses was added on BFT treatments as the organic carbon source at a C/N ratio of 15. Control treatments of each density tested showed more fluctuated water quality parameters throughout the experimental period. The highest TAN and nitrite-nitrogen were observed in control treatment at a stocking density of 100 fish/m 3 (3.97 mg TAN/L and 9.29 mg NO 2 -N/L, respectively). The highest total yield was observed in control treatment at the highest density treatment (43.50 kg), whereas the highest survival was obtained by BFT treatment at a density of 25 fish/m 3 (97.78 + 0.77%). Total feed used in BFT was lower than that of control treatments in particular at 50 fish/m 3 density (P

Biodiesel Production From Algae to Overcome the Energy Crisis

Abstract: The use of energy sources has reached at the level that whole world is relying on it. Being the major source of energy, fuels are considered the most important. The fear of diminishing the available sources thirst towards biofuel production has increased during last decades. Considering the food problems, algae gain the most attention to be used as biofuel producers. The use of crop and food-producing plants will never be a best fit into the priorities for biofuel production as they will disturb the food needs. Different types of algae having the different production abilities. Normally algae have 20%–80% oil contents that could be converted into different types of fuels such as kerosene oil and biodiesel. The diesel production from algae is economical and easy. Different species such as tribonema, ulothrix and euglena have good potential for biodiesel production. Gene technology can be used to enhance the production of oil and biodiesel contents and stability of algae. By increasing the genetic expressions, we can find the ways to achieve the required biofuel amounts easily and continuously to overcome the fuels deficiency. The present review article focusses on the role of algae as a possible substitute for fossil fuel as an ideal biofuel reactant.

Diversity of Pollinator Insects in Relation to Seed Set of Mustard (Brassica rapa L.: Cruciferae)

Abstract: Pollinators provide key services to both natural and agricultural ecosystems. Agricultural productivity depends, in part, on pollinator populations from adjacent seminatural habitats. Here we analysed the diversity of pollinator insects and its effect to seed set of mustard (Brassica rapa) planted in agricultural ecosystem near the Gunung Halimun-Salak National Park, West Java. At least 19 species of insects pollinated the mustard, and three species, i.e. Apis cerana, Ceratina sp., and Apis dorsata showed a high abundance. The higher abundance and species richness of pollinators occurred at 08.30-10.30 am and the diversity was related to the number of flowering plants. Insect pollinations increased the number of pods, seeds per pod, seed weights per plant, and seed germination. Key words: diversity, pollinator insects, social bees, solitary bees, seed set, Brassica rapa