Comparison of two edible mushroom extract as aquaculture feed additives to enhance immune response of Asian seabass

Limitation of antibiotic practice in aquaculture has created attention to uses of organic immuno-stimulant for growth and survival of juveniles with the development of immune system. The purpose of this study was to evaluate the effects of two edible mushroom extracts, Pleurotus sajor-caju and Schizophyllum commune as feed additive in the diets of Asian seabass (Lates calcarifer) juvenile on serum antibody production. Three experimental diets were formulated with 1% inclusion of P. sajor caju (D1), S. commune (D2) and commercial diet without inclusion of mushroom additive was used as a control (D0). Asian seabass juveniles with average weight of 3±1 g were fed for 30 days. Each juveniles were challenged with 0.1ml bacteria suspension consisted of 108 cfu/ml of Vibrio harveyi. Mortality was observed for 10 days after fishes being challenged. Blood was collected before and on third day of challenged, and serum was used to determine antibody titre. Survival rate of D0, D1 and D2 was 60%, 55% and 80%, respectively. Serum agglutinating antibody titer of D2 significantly showed the highest antibody production followed by D1 and D0. Considering the good performance of S. commune in the present study, this mushroom can be considered as potential feed additive in the diets for enhancing immune response in Asian seabass juveniles challenged with V.harveyi

Effects of cage culture on dissolved inorganic nutrient and surface sediment composition in Sulaman Bay Lagoon, Sabah, Malaysia

The major nutrient inputs into Sulaman Bay lagoon are wastes from a nearby village together with particulate organic matter and surface sediment as runoff from mangrove area, as well as from aquaculture activities. The main objective of this study was to determine the dissolved inorganic nutrients (DIN) of water and nutrients of surface sediment in Sulaman Bay lagoon. The data could be was used in developing management strategies for the sustainable aquaculture activity in lagoon ecosystem. Water sample and surface sediment were collected from six stations: five located inside the lagoon and one station at a point that connected the lagoon with South China Sea. The parameters determined included ammonium-nitrogen (mg/L), nitrate (mg/L) and phosphate (mg/L) in water, and particle size, total nitrogen (mg/g), total phosphorus (mg/g), total organic carbon (%) and total inorganic carbon (%) as carbonate equivalent in sediment samples. The highest concentrations of 0.072 mg/L nitrate, 0.121 mg/L of ammonium-nitrogen and 0.058 mg/L of phosphate were obtained from the sea opening point, station nearby village with mollusk culture and village waste drainage areas respectively. Sediment in the Sulaman Bay lagoon was mainly in the form of silt, sand and gravel. The values of total nitrogen and total phosphorus (mg/100g of sediment) were observed to be higher than the values obtained in all stations located inside lagoon. No significant (p>0.05) differences was observed in the total nitrogen of sediment among the stations located inside the lagoon. The highest total organic carbon (TOC) of 22.5% was observed in stations near to the village and cage culture area. The highest value of TOC from the aforesaid stations were significantly different (P 0.05) from the TIC values at other stations. However, the concentration of organic carbon, total nitrogen and total phosphorus in the sediment was higher not only due to commercial cage culture, but also from other human induced activities such as discharge waste from the village, and leafy material with surface sediment as runoff from nearby mangrove vegetation

Surface sediment particles structure of Marudu Bay, Sabah, Malaysia

Sediment can be classified into three major categories: sand, silt and clay, which has a crucial impact on bottom marine life. In other words, different marine organisms prefer different sediment particle structure and texture, reflecting energetics of transport and deposition processes in the water column. The aim of this study is to determine the surface sediment particle structure and its texture in Marudu Bay. Surface sediments were collected from 10 stations which covered the coastal (ST1, ST2, ST3, ST6 and ST10) and the middle (ST4, ST5, ST7, ST8 and ST9) areas of the bay by using the Ponar© (WILDCO®, 6 inch) grab sampler. Subsequently, the sediment samples were then analysed with LISST-Portable Laser Diffraction Particle Size Analyser (Sequoila, WA). The results show coastal areas near river mouths have a coarser particle structure with very slightly clayey silty sand texture compared to stations away from river mouth. The pattern is consistent with the resuspension of finer particles from the sand, silt and clay within shallow turbulent coastal water, and transport across the deeper area of the bay. This finding can contribute to baseline information, and suggests that further understanding of the sediment hydrodynamic across the bay is required for management of the system

Potentiality of Bioconverted Leafy Vegetable Waste as Aquaculture Feed Supplement

Purple non-sulfur bacteria (PNSB) are well known for their ability in transforming organic substrates for their own source of nutrients. The nutritional values of leafy vegetable waste could be improved through bioconversion with PNSB. This study was conducted to access nutritional status of leafy vegetable waste bio-converted product and efficacy of derived product as aquaculture feed supplement. Proximate compositions of bio-converted leafy vegetable wastes were improved after 6 days with 30% inoculums of Afifella marina strain ME (KC205142). The crude proteins (%) and ashes (%) in derived product was increased to 51.7% and 19.6% respectively. On the other hand, the fiber (%) in the bio-converted derived product was decreased by 21%. During feeding trial in Tilapia (Oreochromis niloticus), no significant differences were observed in the feed intake (g/fish/day), but significant differences were observed in the value of feed conversion ratio and weight gain (%) among the used diets. However, lower ingestion rate (g/d/fish) and better feed conversion ratio were obtained while fishes were fed with diet composed of commercial feed mixed with 5% of the bio-converted product. The higher ingestion rate (g/d/fish) and lower feed conversion ratio were observed with only commercial diet. There observed no significant differences in the ingestion rate (g/d/fish) and FCR values among the diet composed of commercial feed with 5% (D5) and 10% (D10) of the bio-converted product. The derived bio-converted product can be a promising approach to open new market segment in aquafeed industry

Efficacy of purple non-sulfur bacterium Afifella marina strain ME to control dissolved inorganic nutrients in aquaculture system

Experiment was conducted to determine the possibility of using locally isolated purple non-sulfur bacterium Afifella marina strain ME to improve the dissolved inorganic nutrients (DIN) in Tilapia Oreochromis niloticus culture tank. The experiment was conducted for seven days without changing water. Ammonia (mg/L), nitrite (mg/L), nitrate (mg/L) and phosphate-phosphorus (mg/L) in the Tilapia culture tank were monitored. Sixteen tails of Oreochromis niloticus juveniles with mean weight of 0.7±0.05g were stocked in ten liter aquarium. Juveniles were fed with commercial feed twice daily by ad-libitum feeding method. Purple non-sulfur bacterium Afifella marina strain ME, and established probiotic commercial Bacillus with four inclusion levels, 0.005(g/L), 0.01(g/L), 0.02(g/L), and 0.03(g/L) were added everyday into culture tank. At the end of experiment no significant difference (P > 0.05) were observed among all the inclusion levels with the concentration of ammonia, nitrite, nitrate and phosphate. The lowest concentration of ammonia, nitrite, nitrate and phosphate were observed in both Afifella marina strain ME, and commercial Bacillus with the inclusion level of 0.03g/L. Obtained results were comparable with commercially established probiotics Bacillus sp. Locally isolated purple non-sulfur bacterium Afifella marina strain ME could be one of the potential candidate in controlling dissolved inorganic nutrients in aquaculture system

Antioxidant properties and antimicrobial activity in the extracts of two edible mushroom, Pleurotus sajor caju and Schizophyllum commune

Extracts of two edible mushrooms, Pleurotus sajor-caju (commercial) and Schizophyllum commune (wild) were used to compare the antioxidant and antimicrobial properties. Aqueous and three types of organic solvents, like 50% of ethanol, methanol and acetone extracts were used in trial. DPPH scavenging activity in P. sajor-caju extract was determined in the range of 53.13% to 85.08%, whereas extracts of S. commune were observed in the range of 54.11% to 97.19% at a concentration of 5 mg/ml. The highest DPPH scavenging activity of 97.19% was observed in ethanol extract of S. commune (97.19%), higher than butyl hydroxytoluene (BTH). Half effective concentration (EC50) in extracts of P. sajor-caju was found in the range of 1.47 to 4.23 mg/ml and that of S. commune in the range of 1.52 to 4.52 mg/ml. The reducing power of P. sajor caju aqueous concentration extract was found to be the closest of 3.353 (700 nm) that of antioxidant activity to BHT (3.445) at 2 mg/ml concentration. The best reducing power EC50 was obtained in P. sajor caju aqueous extract (0.09 mg/ml), but in S. commune with acetone extract (0.22 mg/ml). Minimum inhibition concentration (MIC) was compared in extracts of mushrooms in various Vibrio species. All extracts were able to inhibit V. harveyi growth with MIC of lower than 1.25 mg/ml. In aqueous and methanol extracts of current study showed that bacteria inhibition activity occurred at the concentration of <1.25 mg/ml to 10 mg/ml. Aqueous extract of P. sajor-caju was able to act as reducing agent as functional as the commercial antioxidant agent, BHT. Crude extracts of P. sajor-caju and S. commune were observed to contain antibacterial potential against these mentioned Vibrio bacteria

Characterization of Finfish Hatchery Waste for Value Added Product

Commercial fish hatchery generates waste both organic and inorganic; the sources are primarily from uneaten food and fish feces. Conventional methods of treating hatchery wastes will increase the operating cost and become extra burden in production. It is necessary to develop a new research application of this nonconventional resource and reduce the negative impacts of hatchery waste on the environment. The whole project is to utilize hatchery waste through bioprocess for probiotic fortified live feed production. In this study, the chemical composition of hatchery waste was determined to understand the suitability waste to get value-added derived products through bioprocess. Composite samples were collected everyday and dried in an oven at a temperature of 65˚C until complete dryness. Dried samples were mixed well and grinded into fine powder. The analytical parameters like total solids, ammonium nitrogen, nitrite, nitrate and phosphate were determined from the freshly collected samples. Total nitrogen, total phosphorus and total potassium were determined from the dry samples. Total solids, ammonium nitrogen, nitrite, nitrate and phosphate-phosphorus were observed in the ranged from 75 - 82 mg/L, 0.25 - 8.5 mg/L, 0.05 - 1.9 mg/L, 0.04 - 6.7 mg/L and 4.1 - 16.7 mg/L respectively. On the other hand, the mean content of 3.75% total nitrogen, 1.80% total phosphorus and 0.15% potassium were determined in dry hatchery wastes. The analytical parameters are useful and demonstrate that the nutrients in both fresh and dry waste will be supportive for the growth of microbes in the bioprocess system

Effects of inoculum size of afifella marina in the bioprocessing of sargassum spp. meal

Brown seaweed, Sargassum spp. is also used as an alternative feed ingredient for aquaculture in the form of seaweed meal. Nutritional values seaweed meal with bioprocess technology using microbes such as Lactobacillus , Bacillus or Streptococcus , are improved with different inoculum sizes. Purple non-sulphur bacterium, Afifella marina could be one of the alternative and potential candidates. This study aims to determine the optimum inoculum level and period for the improvement of nutritional values in Sargassum polycystum meal. Sargassum polycystum was collected from the Sepanggar Bay. Dried seaweed was grinded into fine particles ( 0.05) were observed among the values of crude protein, ash, lipids and fiber within 6th and 8th day. A. mariana with 30% (v/v) inoculum sizes on 6th of day has capability in improving the nutritional values of Sargassum polycystum seaweed meal during bioprocessing

Reproductive Biology and Spawning Pattern of Oyster Magallana bilineata in Mengkabong Bay, Sabah, Malaysia

Magallana bilineata is a commercially important oyster species in Malaysia. Despite its economic significance, the biology and ecology of this species, particularly its reproductive cycle, are poorly understood in the region. Therefore, this study aimed to investigate the reproductive cycle of M. bilineata in Mengkabong Bay, Tuaran, Sabah and its correlation with environmental factors. A total of 105 oyster specimens were collected and examined to determine the sex ratio, gonad developmental stages, maturity index (MI), and condition index (CI). The results revealed a sex ratio of 1:2.36 (♂:♀) in the oyster population of the bay, with a significantly higher proportion of females (P < 0.05). Hermaphroditism was detected in 1.90% of the samples. M. bilineata was found to spawn throughout most months in the bay, with the highest MI and CI values recorded in November 2019 when most oysters were in mature or maturing stages. Salinity was found to be the primary factor influencing male gonad maturation, while temperature was the primary factor influencing female gonad maturation. Understanding the reproductive biology of this species is crucial for predicting its future survival and facilitating assisted spawning and hatchery spat production, thereby ensuring the conservation and sustainability of the oyster fishery in Malaysia

Variations in the Physicochemical Water Parameters and Phytoplankton Community in Coastal Water of Kudat, Sabah, Malaysia

This study was conducted to observe the abundance and distribution of phytoplankton and temporal and spatial variation physico-chemical water parameters in coastal water of Kudat, Sabah, Malaysia. Water samples and in-situ water quality parameters were taken from five selected locations from May 2019 to February 2020. The sampling location was selected based on human-induced activities such as Marina Resort’s Jetty (ST1), Sabah Ports’ Jetty (ST2), aquaculture cage/pent (ST3), river’s mouth (ST4) and Landung Ayang’s water village (ST5). Water parameters: pH, salinity (ppt), dissolved oxygen (mg/L) temperature (˚C) and depth (m) were recorded once every month from the selected station. Identification of phytoplanktonic species and cell density (cell/mL) were determined from collected water samples. Significant differences (p < 0.05) between physicochemical parameters to months were observed during the study period. However, in spatial variations, significant differences (p < 0.05) of pH, dissolved oxygen (mg/L) and temperature (˚C) observed. A total of 21 phytoplankton species were identified from the study area, where 4 species belonged to Dinophyceae (HABs blooming species) and 17 species belonged to Bacillariophyceae. The influences of physicochemical water parameters were not significant in phytoplankton diversity and abundance. In addition to these parameters, the nutrients in the water might have important roles in the blooming of phytoplankton, which are essential and vital to address in this type of research