Specific Growth Rate Research Articles

Effects of Atractylodes macrocephala polysaccharide on growth performance, serum biochemical indexes, and intestinal microflora of largemouth bass (Micropterus salmoides)

IntroductionAs the aquaculture industry intensifies to enhance production efficiency and capacity, the risk of disease outbreaks in high-density systems, such as those for largemouth bass, has escalated. This necessitates the exploration of novel strategies for disease prevention and control. Studies have shown that Atractylodes macrocephala polysaccharide (AMP) possesses the functions of promoting growth and enhancing immune capacity, making it a potential feed additive in animal production.MethodsThis study aimed to assess the impact of AMP on the growth performance, serum biochemical indices, and intestinal flora structure of largemouth bass. A total of 360 healthy largemouth bass (mean weight: 15.25 ± 1.29 g) were randomly assigned to four groups, each with three replicates. The groups were fed diets supplemented with 0% (Group D, control group), 0.4% (Group A), 0.8% (Group B), or 1.2% (Group C) AMP for 42 days.ResultsThe results showed that the addition of an appropriate amount of AMP in the feed significantly improved the weight gain rate (WGR) and specific growth rate (SGR) of largemouth bass, reduced the feed conversion ratio (FCR), and enhanced growth performance. AMP reduced the levels of AST and ALT, indicating a hepatoprotective effect on largemouth bass, with significant differences from the control group (P < 0.05). AMP also improved the intestinal microbiota composition of largemouth bass, positively affecting intestinal health. The analysis of intestinal microbiota revealed 1,288 amplicon sequence variants (ASVs) in the intestine of largemouth bass in Group B, dominated by Firmicutes and Bacteroidota. In contrast, Group C (1.2%) had 920 ASVs, with Fusobacteriota and Firmicutes as the major components, while the relative abundance of Firmicutes was lower, showing significant differences from the control Group D. The functional analysis of intestinal microbiota based on KEGG showed significant differences (P < 0.05) among the four groups in Carbon metabolism, Biosynthesis of amino acids, and Metabolic pathways.DiscussionThe study concludes that the inclusion of AMP at 0.8% – 1.2% in the feed can enhance the growth performance and intestinal health of largemouth bass, offering a promising strategy for disease prevention and control in intensive aquaculture settings.

Response of submerged macrophytes of different growth forms to multiple sediment remediation measures for hardened sediment.

Climate change and intensified human activities have disrupted the natural hydrological regime and rhythm of river-connected lakes, extending the dry season, increasing water loss, and exposing previously submerged lake floors. This exposure has led to significant sediment hardening, which directly impacts submerged macrophytes. However, strategies to mitigate the negative effects of hardened sediments and promote the growth and development of submerged macrophytes remain largely unexplored. In this study, we selected typical hardened sediment from Dongting Lake to investigate the response of different growth forms of submerged macrophytes to multiple sediment remediation measures (loosening and litter addition) using a mesocosm experiment. The results indicated that loosening alone uniformly benefited all submerged macrophytes by increasing total biomass, relative growth rate (RGR), and the root/shoot ratio. Additionally, loosening altered the root traits of submerged macrophytes, promoting maximum root length (MRL) while reducing average root diameter (ARD). Moreover, different submerged macrophytes exhibited species-specific responses to the combination of loosening and litter addition. Notably, the combination of loosening and adding Miscanthus lutarioriparius litter had an antagonistic effect on the growth of Potamogeton wrightii and Myriophyllum spicatum. The response of functional traits of submerged macrophytes with similar growth forms to the same treatment was consistent. Our findings suggest that future sediment remediation efforts should consider matching specific treatments with the growth forms of submerged macrophytes to achieve optimal outcomes.

Perspectives on optimizing microalgae cultivation: Harnessing dissolved CO2 and lactose for sustainable and cost-efficient protein production

Microalgae, known for their land-sparing cultivation and remarkable photosynthetic efficiency, play a crucial role in advancing sustainable development goals. This study explored the use of cost-effective inorganic carbon (the ionic form of CO2) and organic carbon sources (lactose, a primary sugar in whey wastewater) to support the growth of Chlorellasorokiniana UTEX 1230, and improved protein content through nitrogen supply optimization. NaHCO3 proved to be more effective than Na2CO3, resulting in a 3.4-fold increase in biomass concentration, with an initial 5 mM HCO3‾ concentration compared to the basal medium. Further addition of 0.75 % lactose led to a 4.05-fold increase in biomass concentration, with the maximum specific growth rate at 1.28/d, maximum biomass concentration at 695.88 mg/L, and maximum biomass productivity at 250.91 mg/L/d. Nitrogen supplementation greatly increased protein concentration from 16.41 % (250 mg/L NaNO3) to 52.95 % (1000 mg/L NaNO3). These results support the potential for utilizing whey wastewater bioremediation to produce high-value protein via microalgal cultivation.

Growth of Oncorhynchus mykiss (Rainbow Trout) through a Recirculation System in the Foothills of the Extreme North of Chile.

Given the overexploitation of fisheries and the growing consumption of sea products, aquaculture is emerging as an alternative to meet the demand for protein at regional, national, and global levels. In northern Chile, the foothills of the Andes offer an opportunity for sustainable economic diversification. In this study, results of a rainbow trout (Oncorhynchus mykiss) culture in a recirculation system are presented, analyzing its growth and performance under altitude conditions. The research was carried out in Copaquilla, a small area in the foothills of northern Chile, 3000 m above sea level. Five thousand 15 g juvenile trout were acquired and transported by land from the Rio Blanco fish farm, successfully traveling more than 2100 km. During the 20-month-long culture, several growth parameters were evaluated, including specific growth rate, percentage of weight growth, feed conversion factor, survival, and Fulton's condition factor. All these parameters were within the normal growth range for trout, evidencing good-quality growth of the organisms. The results offer evidence that rainbow trout farming at 3000 m above sea level is viable and presents a viable performance, opening new opportunities for aquaculture in northern Chile.

The Effect of Acrylonitrile Butadiene Styrene (ABS) and Polypropylene (PP) Microplastics on Ulva lactuca L. and Ceramium diaphanum R. Algal Growth

The goal of this study was to determine the effects of acrylonitrile butadiene styrene and polypropylene microplastics as two typical classes for microplastic pollution on algal growth, lipids, carbohydrates, chlorophyll-a and total carotenoid content of Ulva lactuca L. and Ceramium diaphanum R. collected from the Gulf coast of Izmir province. The results demonstrate that ABS-MPs had no statistical effect (P>0.05) on the various physiological parameters of U. lactuca macroalgae after 5 days of exposure, except for the total carbohydrate and lipid concentration. The chl-a value of C. diaphanum was considerably increased under the low concentration of ABS (25 mg L-1), increasing by 81.56% compared with the control while the amount of chl-a decreases (32.05%) in parallel with the increasing concentration of PP-MPs. Laboratory incubation experiments showed that MPs affect relative growth rate, pigments efficiency or carbohydrate content of C. diaphanum until reaching an extremely high concentration (100 mg L-1), indicating a high tolerance to MPs. The results showed that two macroalgae species, especially U. lactuca, were not highly affected at low MPs concentrations under laboratory conditions which were much higher than the levels of environmentally relevant concentrations.

Growth of Vaname Shrimp (Litopenaeus vannamei) Infested with Extracts of Ectoparasites Chlorella vulgaris as an Immunostimulant

Abstract Vannamei shrimp (Litopenaeus vannamei) has a high market demand, encouraging production to minimize stress, water quality degradation and disease attack. Ectoparasite attacks come from the genera Epistylis, Zoothamnium, and Vorticella. Body defense through immunostimulants from Chlorella vulgaris extract which has bioactive compounds, vitamins and proteins. The purpose of the study was to determine the effect of giving Chlorella vulgaris extract with different doses and length of maintenance, as well as the interaction of Chlorella vulgaris as an immunostimulant on the growth of vaname shrimp infested with ectoparasites. The research method used a complete randomized experimental design with a factorial pattern consisting of factor A, the dose of Chlorella vulgaris extract, namely without giving Chlorella vulgaris extract (A0), 400 mg/kg (A1), 800 mg/kg (A2), 1200 mg/kg (A3) and factor B, the length of shrimp rearing, namely 0 days (B1), 7 days (B2), 14 days (B3), 21 days (B4), 28 days (B5). This study uses three variables, namely independent variables administration of Chlorella vulgaris Extract and length of maintenance, bound variables Survival (SR), Specific Growth Rate (SGR) and Absolute Growth (GR) and Absolute Growth (GR), and control variables water quality (temperature, pH, dissolved oxygen, salinity, and ammonia). The results of the study at dose A2 with length of rearing B5 gave a real effect (p<0.05) on the growth of vaname shrimp infested with ectoparasites, namely survival (50%), specific growth rate (4,17%), and absolute growth (weight (1,39 grams), length (1,10 cm)).

Monitoring water quality parameters impacted by Indonesia’s weather using internet of things

Increasing need for food resources, State of Indonesia to strive to maximize the output of food production. Not only in agriculture but also aquaculture results are also trying to be improved. This is also supported by the increase of Indonesia’s national fish consumption rate from 50.69 Kg per capita in 2018 to 55.37 Kg per capita in 2021. Recent aquaculture research only explored topics about monitoring the cultivation environment. But there have been no studies exploring how bad the impact of weather on the process of farming. Hence, this study aims to measure the influence of weather on freshwater aquaculture pond water quality and analyze its impact on fish growth namely Oreochromis Sp., using pH sensors and dissolved oxygen (DO). Then a weather simulation was carried out based on Indonesia’s tropical climate, which majorly consists of sunny and rainy weather. The experimental results indicate the instability of the pH value during the rainy period. DO values tend to decrease at the end of periods of sunny weather. Moreover, fish growth analysis showed that there was a decrease in food conversion ratio (FCR) by 0.956, specific growth rate (SGR) by 2.13% and survival rate (SR) by 5.715% during rainy weather.

Study on Pasir Lobster Enlargement (Panulirus homarus) to Improve Cultivation Productivity with Keong Bakau (Telescopium telescopium)

Abstract The potential of lobster in Indonesia is very high, the demand for lobster continues to increase every year, while the supply still utilizes the catch of fishermen. Lobster utilization in Indonesia is still low, therefore there must be sustainable cultivation in order to increase the quantity and quality of lobsters in Indonesia. One way to increase lobster enlargement is by feeding Keong Bakau. The purpose of this study is to determine and improve Lobster Pasir enlargement, including enlargement management, water quality management, and feed management with Keong Bakau. The study was conducted at the Lombok Marine Aquaculture Center, in Indonesia. The method used is a descriptive method with a quantitative approach. The feed used was Keong Bakau. The survival rate (SR) value reached 100%, the specific growth rate (SGR) value was 0.002%, and the FCR value was 23.82. The amount of feed given is sufficient for the needs of the lobster, the Keong Bakau used has chitosan which can help support the survival of the lobster. The average results of water quality include temperature (28.06oC), pH (7.07), DO (7.34 mg/l), Salinity (32.9 ppt), Turbidity (2.66 m), Phosphate (0.175 mg/l), Nitrite (0.002 mg/l), Nitrate (0.02 mg/l), and Ammonia (0.055 mg/l). DO values were slightly different from the optimal range due to the reduced intensity of vessels passing through the KJA. Keong Bakau has calcium which plays an important role in the formation of the exoskeleton in lobsters after the molting process.

The Effect Of Stocking Densities On Growth And Survival Rate Of Thai Mahseer (Tor Tambroides) During Nursery Stage.

Abstract Tor Fish are freshwater fisheries resources that have the potential to be found in Indonesia. Tor fish has been in high demand among entrepreneurs and the broader public. Tor tambroides (Sapan fish or Thai mahseer fish seed fish), Tor douronensis (Semah or Garing fish), Tor soro (Soro, Lempon, or Dewa fish), and Tor tambra are the four kinds of Tor fish native to Indonesia. Tor fish is a native indigenous freshwater fish from Indonesia that is on the verge of extinction. The Tor tambroides fish population in nature has declined and is on the verge of extinction as a result of widespread poaching for eating and trade as an ornamental fish. Thai mahseer fish seed fish cultivation activities include hatchery, nursery and enlargement. To protect populations of Thai mahseer fish seed fish from scarcity, Thai mahseer fish seed fish cultivation needs to do to prevent the scarcity of Thai mahseer fish seed fish in their natural habitat and Thai mahseer fish seed fish have high potential as freshwater fish in the aquaculture sector. This research aims to determine the impact of various stocking densities on growth and survival rates for Thai mahseer fish seeds, as well as the optimal density to support growth and survival rates. The study used a Random Design Complete (RDC) with four treatments and five replications. Feeding was provided ad libitum in the morning and evening. Given differences in the stocking density of Thai mahseer fish seeds, the results revealed a significant impact on all treatments. Treatment 1 had the greatest daily growth rate with a stocking density of 2 seeds/L and a yield of 0.015±0.003; specific growth rate. The highest absolute weight growth obtained was in Treatment 1 with a yield of 1.01gr; the highest absolute length growth obtained was in Treatment 1 with a yield of 2.9cm; and the highest survival rate for Thai mahseer fish seeds was obtained in Treatment 1 with a yield of 80%.

The Effect of Use of Cow Manure on the Growth of Two Cultivars of Glycine Max L. Using a Verticulture Planting System

This study aims to provide data on the verticulture method planting and the use of cow manure to black soybeans (Glycine max L.). This study used a factorial Randomized Block Design (RAK) containing two factorials and four replications. K1 refers to the unit 1 soybean cultivar, while K2 stands for the pearl 2 cultivar. One of the cultivar factors is this (K). Inside the interval (P), we find three values: P1= 0 kg, P2= 0.18 kg, and P3= 0.32 kg. “Among the variables that underwent changes were plant height, leaf count, leaf area index, chlorophyll content, relative growth rate (LPR), net assimilation rate (LAB), and active root nodules. According to the results, there was no significant difference between using 0.16 kg/bed of organic fertilizer or no fertilizer at all when measuring plant height at 7, 14, 21, 28, 35, and 42 HST for Cultivar K1 (detam 1)”. The availability of organic fertilizer at 0.32 kg/bed was significantly affected by manure at 7, 14, 21, 28, 35, and 42 HST at the third dosage. The results of this study show that neither cultivar 1 nor pearl cultivar 2 had any discernible impact on the vegetative development of black soybean plants when manure was applied at dosages of 0 kg, 0.16 kg, and 0.32 kg.

Hepatic artery restriction operation combined with ALPPS (HARO-ALPPS), a novel ALPPS procedure for the treatment of hepatocellular carcinoma with severe fibrosis: retrospective clinical cohort study.

Associating liver partition with portal vein ligation for staged liver resection (ALPPS) has been used in the treatment of patients with advanced or massive liver cancer without sufficient future liver remnant, but concerns remain regarding tumor outcomes and surgical safety. This study aims to evaluate the efficacy and safety of a new procedure, hepatic artery restriction operation combined with ALPPS (HARO-ALPPS), in the treatment of hepatocellular carcinoma (HCC) patients especially with severe fibrosis. This retrospective study analyzed 8 patients who underwent HARO-ALPPS for HCC and compared their outcomes with 64 patients who underwent conventional ALPPS. The primary outcomes assessed were liver regeneration ability (measured by relative and absolute kinetic growth rates), postoperative complications, and mortality. The secondary outcomes included overall survival and disease-free survival. HARO-ALPPS significantly restricted the blood supply of the hepatic artery. One week after surgery, the blood flow of the right hepatic artery dropped to 62.1%. At the same time, HARO-ALPPS shows superior liver regeneration ability, which is particularly prominent in the background of liver fibrosis. No serious complications occurred after HARO-ALPPS. The overall survival rate of HARO-ALPPS was 75%, which was higher than that of ALPPS (64%, P =0.816). Compared to conventional ALPPS, HARO-ALPPS exhibits a better liver regeneration ability, and favorable long-term outcomes. Further prospective studies are needed to validate these findings and evaluate the long-term oncologic outcomes of this novel procedure.

Evaluation of gouramy fish (Osphronemus goramy) hatchery in Pandaan Aquaculture Installation, Pasuruan

Abstract Gourami fish is well-known among the public due to its economical impact, good tastes, and easy to cultivate. This study aimed to determine the performance of gourami hatcheries at the Pandaan Aquaculture Installation. The method in this research used active participation and descriptive methods. The data collection method used was from primary and secondary data. The evaluation results showed that hatchery activity there produced a fertilization rate of 97.6%, hatching rate of 95.3%, survival rate of 91.3%, and specific growth rate of 7.85%. Water quality in hatchery activities also met standards. Gouramy hatchery activities included pond preparation, broodstock preparation, brood spawning, egg harvesting, egg hatching, larval and seed rearing, nursery, water quality monitoring, feed management, and pest and disease management. It can be concluded that hatchery activity at Pandaan Aquaculture Installation shows good performance.

Efficient butanol production from sweet sorghum stem juice by a co-culture system at an optimum temperature: Insights from oxidation-reduction potential monitoring and pilot scale validation

A two-stage co-culture approach was employed in an acetone-butanol-ethanol (ABE) fermentation. An obligate aerobic bacterium, Arthrobacter sp., was first grown for 6 h at 30 °C to create anaerobic conditions. Subsequently, Clostridium beijerinckii TISTR 1461 was inoculated and a fermentation was performed at 37 °C. To identify an intermediate temperature suitable for both microorganisms, their growth was examined at 30, 34, and 37 °C. C.beijerinckii exhibited the highest specific growth rate at 37 °C, while Arthrobacter sp. displayed similar growth rates at all tested temperatures. Butanol production from a synthetic medium (P2 medium) by C. beijerinckii at different temperatures using oxygen-free nitrogen (OFN) gas flushing as a control treatment revealed that fermentation at 37 °C gave the highest butanol concentration (PB, 9.98 g/L). Consequently, 37 °C was chosen for butanol production from sweet sorghum stem juice (SSJ) by co-culture of these two microorganisms in 1-L screw–capped bottles. Compared to the control treatment, higher PB (11.38 g/L), yield (YB/S, 0.37 g/g) and productivity (QB, 0.24 g/L·h) were achieved using the co-culture system. These results were further confirmed by monitoring the oxidation–reduction potential (ORP) during ABE fermentation in a 2-L stirred-tank bioreactor (STR). Moreover, when the co-culture fermentation at 37 °C was scaled up in a 30-L STR, the PB, YB/S and QB values were comparable to those obtained in the 2-L STR. Therefore, co-culture fermentation of Arthrobacter sp. and C.beijerinckii TISTR 1461 at 37 °C represents a promising method for large-scale butanol production.

Isolation and characterization of a strain Clostridium butyricum B3 from the intestine of Pelteobagrus fulvidraco and its potential probiotic roles

The use of host-associated probiotics in aquaculture have been limited due to difficulties in their isolation from the host gastrointestinal tract and validation of their biological function. Here, anaerobic Clostridium butyricum strain B3 was isolated for the first time from the intestines of yellow catfish (Pelteobagrus fulvidraco). Alignment of 16 S rDNA sequences revealed 99 % identify between strain B3 and wild-type C. butyricum. C. butyricum B3 was found to tolerate a wide range of temperature (up to 80 °C) and pH (1 to 13) levels. In vitro microbial growth experiments revealed that C. butyricum B3 produced acetic acid (890.00 ± 23.00 mg/L) and butyric acid (672.67 ± 51.67 mg/L) highly productively within 24 h. Further in vitro characterization findings also suggested that C. butyricum B3 is sensitive to several antibiotics, including ampicillin and chloramphenicol, and potently inhibits the growth of pathogenic bacteria such as Aeromonas hydrophila. In a feeding experiments, 30 days of dietary supplementation with 3.0 × 107 to 109 CFU/g B3 significantly increased the specific growth rates of yellow catfish juveniles by more than 61.5 %. Activities of trypsin, α-amylase and lipase were significantly enhanced in group fed with 3.0 × 107 B3 compared to the control group (P < 0.05). Furthermore, ACP activity was significantly increased by more than 25.0 %, whereas malondialdehyde content significantly decreased by at least 38.5 % in all B3 feeding groups (P < 0.05). In addition, hepatocyte density increased, and goblet cells in the intestinal epithelial cells expanded. Meanwhile, C. butyricum B3 feeding significantly activated genes (such as grhpr and enpp2) involved in lipid metabolism and proliferator-activated receptor signaling pathway, increased bacterial diversity, and reduced the bacterial richness of the gut microbiota (P < 0.05). In conclusion, dietary inclusion of 3.0 × 107 CFU/g of C. butyricum B3 enhanced the growth performance, immune response, and lipid metabolism of P. fulvidraco.

Agrometeorological indices, physiological growth parameters and performance of finger millet as influenced by different cultivars under hot and sub humid region of Odisha

Present-day agriculture is under tremendous pressure due to various factors such as climate change, degradation of soil and water quality, and yield plateauing of major food crops. Under these scenarios, there is an urgent need to choose a climate-resilient and ecologically hardy crop which can perform under adverse conditions with low input requirements. In this regard, millets can be suitable crops for agricultural sustainability. Among various millets, finger millet (Eleusine coracana L. Gaertn) is cultivated mainly in India and Africa. However, most farmers grow finger millet with local cultivars, and improved ones can be replaced to enhance productivity. The present investigation conducted at the Post Graduate Research Farm of Centurion University of Technology and Management, Odisha, focused on evaluating suitable cultivars of finger millet. The study revealed that cultivars significantly influenced finger millet growth, productivity, and economics. The physiological growth parameters, namely, crop growth rate, relative growth rate, net assimilation rate and leaf area duration were significantly influenced by finger millet cultivars. The growing degree days (GDD), helio-thermal units (HTU) and photothermal units (PTU) of the finger millet showed a great variation among the cultivars. The Maximum total GDD (2169 °C day), HTU (18141 °C day hours) and PTU (24297 °C day hours) were recorded in the cultivar Hima(w) VR 936. The cultivars Indravathi VR 1101, Sri Chaitanya VR 847 (1.73) and Hima (W) VR 936 (1.60) were superior to other cultivars in expression of the grain yield and economics of finger millet. The study concluded that the cultivation of Indravathi and Sri Chaitanya could be considered as short-duration cultivars; however, Hima can be chosen as long duration crop for successful finger millet cultivation with higher net returns and benefit-cost ratio under hot and sub-humid regions of Odisha.

Engineering the cell wall reactive groups of Plant Growth Promoting Rhizobacteria by culture strategy for heavy metal removal

This research delved into the effects of nutrient limitation on the level of sporulation and the cadmium adsorption capacity of the bacterium Bacillus sp. isolated from the rhizosphere of endemic soils in the Region of Valparaiso, Chile. The bacteria were subjected to nitrogen limitation in fed-batch mode and were compared to bacteria grown in batch culture without nutrient limitation. The cultures were carried out in a 3 L bioreactor with an external nitrogen supply of ammonium at a flow of 0.123 L h−1. The specific maximum growth rate was 0.42 h−1 in batch and 0.45 h−1 in the exponential phase of the fed-batch.The analysis of sporulation did not show any significant difference between the biomass coming from the fed-batch and batch cultures.It was found that maximum cadmium adsorption capacity varied with culture strategy. The dry biomass grown without nutrient limitation exhibited a maximum adsorption capacity for cadmium of 65.0 mgCd g−1biomass. Conversely, the limited biomass achieved a lower cadmium adsorption capacity of approximately 36.0 mgCd g−1biomass. FTIR analysis showed that nitrogen limitation induced changes in the composition of the outer cell wall, specifically an increase of deacetlylated polysaccharides, reducing the relative amount of secondary amines and proteins from the peptidoglycan matrix. Amino groups from acetylated polysaccharides and proteins have been associated elsewhere with greater cadmium affinity, which could explain the poor results obtained with the nitrogen-restricted biomass. This study shows that new physiological states displaying different adsorption capabilities were effectively obtained by engineering the cell coverage of the bacteria using varying culture strategies. The fed-batch culture proved to be a valuable tool for studying PGPR strains for biosorption and other applications. Exploring diverse nutrient limitations and other pollutants in this bacterium and other members of the PGPR family offer great opportunities to tailor biosorption strategies based on specific conditions, ultimately contributing to sustainable environmental solutions.

Agro-industrial Waste Utilization, Medium Optimization, and Immobilization of Economically Feasible Halo-Alkaline Protease Produced by Nocardiopsis dassonvillei Strain VCS-4.

The oceanic actinobacteria have strong potential to secrete novel enzymes with unique properties useful for biotechnological applications. The Nocardiopsis dassonvillei strain VCS-4, associated with seaweed Caulerpa scalpeliformis, was a halo-alkaline protease producer. Further investigation focuses on medium optimization and the use of agro-industrial waste for economically feasible, high-yield protease production. A total of 12 experimental runs were designed using Minitab-20 software and Placket-Burman design. Among the 7 physicochemical parameters analyzed, incubation time and gelatin were detected as significant factors responsible for higher protease production. Incubation time and gelatin were further analyzed using OVATs. Optimal protease production was achieved with 2% gelatin, 0.1% yeast extract, 0.1% bacteriological peptone, 7% NaCl, pH 8, 5% inoculum, and a 7-day incubation period, resulting in a maximum protease activity (Pmax) of 363.97 U/mL, generation time of 11.9h, specific growth rate of 0.161g/mL/h, and protease productivity (Qp) of 61.65 U/mL/h. Moreover, utilizing groundnut cake as an agro-industrial waste led to enhanced production parameters: Pmax of 408.42 U/mL, generation time of 9.74h, specific growth rate of 0.361g/mL/h, and Qp of 68.07 U/mL/h. The immobilization of crude protease was achieved using Seralite SRC 120 as a support matrix resulting in 470.38 U/g immobilization, 88.20% immobilization yield, and 28.90% recovery activity. Characterization of both crude and immobilized proteases revealed optimal activity at pH 10 and 70°C. Immobilization enhanced the shelf-life, reusability, and stability of VCS-4 protease under extreme conditions.

Aloe vera leaf (Aloe barbadensis) iron-oxide nanoparticles improved growth performance, immune response and survival of African sharptooth catfish (Clarias gariepinus) challenged with Aeromonas hydrophilia

ABSTRACT Nano-sized essential minerals and nutrients synthesized from plant extracts are being explored for their impact on growth, immune stimulation, and overall fish health. This study evaluated the growth performance, health, and survival of African catfish, Clarias gariepinus, particularly when challenged with Aeromonas hydrophila. Biosynthesized Aloe vera leaf iron oxide nanoparticles (ANP) were confirmed by ultra-violet spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy as nanoparticles. The ANPs were added to the basal diet at 0, 40, 80, 120, and 160 mg/kg, forming five treatments. The fish were fed to apparent satiation twice daily for 84 days. Results showed that dietary ANP improved weight gain, specific growth rate, protein efficiency ratio, and feed conversion ratio significantly with increasing levels of the nanoparticles. Fish fed 160 mg/kg ANP diet had a weight gain of 102.12 ± 18.91 g, while fish fed the control diet had a weight gain of 78.89 ± 22.2 g. Fish quality indices, including head-to-body percentage, visceral-somatic ratio, and flesh ratio, were similar (p > .05) across treatments. Supplementation of ANP improved significantly fish carcass quality and survival rate compared to the control diet. Fish fed nanoparticle diets had significantly different (p < .05) moisture, ash, and protein contents across all treatments. The fat content decreased with increasing nanoparticle levels, with the control diet showing the highest value (14.54%) and 160 mg/kg ANP diet the lowest (12.94%). Dietary ANP also improved carcass iron and zinc contents significantly. Additionally, ANP increased packed cell volume, red blood cells, white blood cells, hemoglobin, and erythrocyte sedimentation count more than the control diet. Alanine transferase, aspartate transferase, catalase, and superoxide dismutase levels increased with ANP in the diets. Fish-fed ANP diets had higher (p < .05) total serum protein than fish fed the control diet. ANP diets reduced blood glucose levels significantly, and cholesterol levels decreased marginally with increasing nanoparticle levels. Conclusively, ANP positively influenced the growth, immunity, and survival of C. gariepinus.

Growth of Tilapia (Oreochromis niloticus) Juvenile strain Nirwana with Different Natural Feeding

The high cost of commercial feed in Nirwana tilapia aquaculture leads to elevated production costs and reduced profits. As a solution, the provision of natural feed is proposed as an alternative to reduce production expenses. This study aims to compare the growth of Nirwana tilapia fed with three different natural feeds: Tubifex sp., Chironomus sp. larvae, and maggots. The experiment was conducted using a completely randomized design with three replicates for each treatment. The feeding rate was 3% of the fish’s body weight, administered three times a day. The parameters measured included absolute biomass, absolute length gain, daily growth rate (Specific Growth Rate, SGR), survival rate (SR), and water quality during the 30-day rearing period. The results showed that feeding Nirwana tilapia with Tubifex significantly increased growth compared to the control group (commercial pellets), Chironomus larvae, and maggots. The absolute biomass from Tubifex feeding was 5.23 ± 0.89 g, absolute length was 4.2 ± 7.8 cm, SGR was 1.52 ± 0.33%, and SR was 90%. The next highest growth was seen in Chironomus larvae, followed by maggots, with the control yielding the lowest results.

Candida boidinii isolates from olive curation water: a promising platform for methanol-based biomanufacturing

Methanol is a promising feedstock for biomanufacturing, but the efficiency of methanol-based bioprocesses is limited by the low rate of methanol utilization pathways and methanol toxicity. Yeast diversity is an attractive biological resource to develop efficient bioprocesses since any effort with strain improvement is more deserving if applied to innate robust strains with relevant catabolic and biosynthetic potential. The present study is in line with such rational and describes the isolation and molecular identification of seven isolates of the methylotrophic species Candida boidinii from waters derived from the traditional curation of olives, in different years, and from contaminated superficial soil near fuel stations. The yeast microbiota from those habitats was also characterized. The four C. boidinii isolates obtained from the curation of olives’ water exhibited significantly higher maximum specific growth rates (range 0.15–0.19 h−1), compared with the three isolates obtained from the fuel contaminated soils (range 0.05–0.06 h−1) when grown on methanol as the sole C-source (1% (v/v), in shake flasks, at 30°C). The isolates exhibit significant robustness towards methanol toxicity that increases as the cultivation temperature decreases from 30°C to 25°C. The better methanol-based growth performance exhibited by C. boidinii isolates from olives´ soaking waters could not be essentially attributed to higher methanol tolerance. These methanol-efficient catabolizing isolates are proposed as a promising platform to develop methanol-based bioprocesses.