Specific Activity Of Amylase Research Articles

Seleksi Bakteri Asam Laktat Pada Fermentasi Spontan Biji Kopi Robusta dan Karakterisasi Enzim

Lactic Acid Bacteria (LAB) are natural bacteria that play an important role in the fermentation process. These bacteria can produce cellulase and pectinase enzymes. This study aims to examine isolates of lactic acid bacteria involved in the spontaneous fermentation of amylolytic robusta coffee beans and to examine the effect of incubation time, pH and temperature on the activity of the amylase enzyme produced. This study used the experimental method with a completely randomized design (CRD). The stages in this study were the preparation of equipment and media, selection of amylolytic LAB, determination of the optimum incubation time, and characterization of the amylase enzyme. The results showed that there were 2 isolates capable of producing clear zones, namely isolates BT2411 and BT2412. The clear zone indicates the presence of amylolytic LAB in the tested isolates. BT24I1 isolate is a LAB isolate which produced the highest clear zone with a diameter of 2.43 mm. Testing the incubation time showed that isolate BT24I1 produced the optimum amylase enzyme at 48 hours of incubation with a specific amylase activity value of 0.64 U/ml. The characteristics of the amylase enzyme produced by BAL BT24I1 isolate are optimum at pH 4.5 with enzyme activity of 19.89 U/ml and optimum at 45℃ with enzyme activity of 19.79 U/ml

Exploring the connection between food and midgut digestive enzymes to improve honey bee (Apis mellifera) nutrition

Honey bee malnutrition is the leading challenge in beekeeping. Finding a high-quality and cheap alternative to polyfloral pollen is essential. To find a quick and cheap analysis that can be used to evaluate different substitutes for pollen in bee nutrition, caged bees were fed with four types of patties based on sugar, yeast, pollen, and Tenebrio molitor flour (SG, YG, PG, and TG group, respectively). Midgut and hindgut weight, as well as amylase and protease activity in the midgut, were measured to evaluate the effect of patties. Midgut weight was lowest in SG except on days 21 and 28 when it was similar to PG, and highest in YG on day 14 and 21. In SG and TG midgut weight didn’t change over time, while in YG it decreased from day 14 to day 28 and PG from day 7 to day 21 and 28. Specific amylase activity was the highest in YG, and lowest in SG, while it decreased in the YG and PG with time. Specific protease activity decreased in all groups comparing day 7 to day 28. PG and TG bees had a higher number of enzyme isoforms in comparison to YG bees, while SG bees had the lowest number of isoforms in contrast to all other groups. Mealworm patty fed bees had the highest protein concentration in the midgut at day 14 and 28, and similar to PG bees at day 21, induced similar enzyme profiles as pollen patty indicating its superiority over YG and SG.

Effect of Scoparia dulcis Extract on Lipid Oxidation in Fish Feed, Growth Performance, and Hypoxia Tolerance in Juvenile Jian Carp (Cyprinus carpio var. Jian).

Lipid oxidation and hypoxia can lead to oxidative damage in aquatic animals. This study explored the effects of Scoparia dulcis extracts (SDE) on lipid oxidation, fish growth performance, digestive ability, antioxidant capacity, and hypoxia tolerance ability. The results showed that SDE decreased malonaldehyde (MDA), conjugated diene (CD), and peroxide value (PO) in the linoleic acid and linolenic acid as well as in fish feed. Broken-line analysis revealed that the optimal acetone extract of S. dulcis (AE) supplements was 4.02, 4.01, and 4.01 g kg-1 determined from PO, CD, and MDA, respectively. Dietary AE supplementation increased feed intake and specific growth rate and activities of amylase, trypsin, and lipase as well as alkaline phosphatase in fish hepatopancreas and gut. Polynomial regression analysis showed that optimal dietary AE supplement was 3.61 g kg-1 diet determined from weight gain. Furthermore, dietary AE supplementation decreased MDA content and increased glutathione content and the activities of glutathione peroxidase, catalase, superoxide dismutase, and glutathione reductase in fish digestive organs, gills, erythrocytes, and muscle. Dietary AE supplementation increased durative time (DT) and oxygen consumption rate (OCR) under hypoxia condition. Based on polynomial regression analysis, optimal dietary AE supplements were 4.73 and 4.60 g kg-1 diet determined from DT and OCR for hypoxia tolerance in fish, respectively. According to our current research, SDE's antioxidant capacity may be attribute to their phenolic chemicals.

Comparative study on the valorization of Sargassum from the Mexican Caribbean coast and Gulf of California as an ingredient on healthy diets for shrimp farming

Sargassum biomass is a potential ingredient for aquaculture formulations due to its high nutritional value and availability, as it contains a variety of essential nutrients including proteins, carbohydrates, lipids, vitamins, antioxidants, fiber, and minerals, which are essential for aquatic growing, development and health parameters including digestibility and immune response against diseases. Therefore, in this work, five experimental diets were formulated considering 2.5 % and 5 % levels of inclusion of Sargassum spp. from the Mexican Caribbean coasts (SC), and from the Gulf of California (SG), and one reference diet as a control. The characterization of the raw material and the proximal analysis of the five diets were evaluated according to standard reference methods. A 35-day feeding trial was conducted using juvenile Litopenaeus vannamei showed a shrimp survival rate of 97 ± 6 % (p > 0.05) on SC. Excellent weight gain (WG) performance of SC and SG diets at 2.5 % of inclusion resulted in >10 % WG compared to the control. The specific activity of amylase, lipase, trypsin, and chymotrypsin showed a significant increase by including Sargassum in diets, compared with the reference diet. Incorporating Sargassum at 2.5 % in feed formulations for shrimps showed a great opportunity to use it as an ingredient and improved production yields. The digestion and absorption parameters were represented by the enzymatic activity in which the diets based on Sargassum spp. from the Mexican Caribbean coast (SC) have resulted in the best performance.

Ontogenetic development of digestive enzymes and in vitro digestibility of spotted Babylon (Babylonia areolata) veligers

The ontogenetic development of the main digestive enzymes and in vitro digestibility were investigated in spotted Babylon (Babylonia areolata) veligers. The collected specimens included fertilized eggs, trochophores, veligers, and settlement stage larvae. The activity of each studied enzyme showed strongly positive pairwise correlations with the activity of every other enzyme studied (r = 0.498–0.847, n = 60, p < 0.01). Pepsin showed the highest specific activity during the development of the veligers (p < 0.05). Pepsin and chymotrypsin specific activity followed broadly similar trends, except in late trochophore and early veliger stages. Trypsin specific activity was highest in early-stage veligers. Amylase specific activity progressively increased in middle-stage veligers, and decreased in older veligers. Cellulase activity started to increase before hatching, exhibiting its highest activity during the first seven days of veliger development. Lipase specific activity increased progressively in early-stage veligers and then decreased and remained constant until the end of observation. The in vitro digestibility assay showed that three mixed rations (75:25, 25:75, and 0:100 w/w) of Chaetoceros sp. and Isochrysis sp., and single components of Spirulina meal, and clam feed were suitable for early-stage veligers, while all mixed rations of Chaetoceros sp. and Tetraselmis sp., and single components of Spirulina meal and herbivorous fish feed were suitable for late-stage veligers. Our findings can be used as a feed management reference for spotted Babylon veligers.

Metabolic turnover rate, digestive enzyme activities, and bacterial communities in the white shrimp Litopenaeus vannamei under compensatory growth.

The present work aimed to evaluate the effects promoted by a phase of compensatory growth on metabolic turnover rate, digestive enzyme activity, and bacterial biota of the Pacific white shrimp Litopenaeus vannamei kept under different feeding regimes. Three treatments were evaluated as follows: 70% feed restriction during 3 (T3) and 6 (T6) days, followed by a period of feeding to satiety, and a control treatment without restriction periods. The results showed a full compensatory growth in treatments T3 and T6 by day 35 of the bioassay. A significant increase in trypsin and lipase (T6) activities was observed during compensatory growth, whereas specific amylase activity was significantly lower in treatment T6 compared to T3 but not significantly different from the control group. To determine the metabolic turnover rate of nitrogen in muscle tissue, an analysis of nitrogen isotope values (δ15N) at natural abundance levels was performed. At the end of the experimental period, shrimp under feed restriction had lower metabolic turnover rates and longer nitrogen residence times (t 50) in muscle tissue, as compared to individuals in the control treatment. Regarding the changes in the bacterial communities in shrimp gut, no significant differences were observed at the phylum level, with Proteobacteria being the most abundant bacteria, followed by Actinobacteria. At family taxa level, Rhodobacteraceae presented the highest relative abundance in all treatments, whereas a decrease in Vibrionaceae was observed in treatments T3 and T6 when compared to control shrimps during compensatory growth. At the genus level, a decrease in Celeribacter, Catenococcus, and Epibacterium, and an increase in Ruegeria and Shimia, were identified in shrimp subjected to feed restriction when compared to control organisms during compensatory growth (day 14). At the end of the experimental period, the evaluated parameters showed similar results as those observed in the control treatment, suggesting a normalization of the metabolism and the physiological state. The present findings contribute to a better understanding on the physiological effects produced during compensatory growth in shrimp, which in turn could assist in the development of improved feeding strategies in benefit of the aquaculture industry.

Wolffia globosa as a biocatalyst in plant-based biofuel cells

The rootless duckweed Wolffia globosa, not explored toward electrogenicity till now, is investigated as a putative biocatalyst in Plant-based Biofuel Cells (P-BFC) for the electrical current generation and its basic metabolic changes during the polarization are depicted. After a short adaptation period, the open-circuit voltage of P-BFC, utilizing W. globosa as an anodic biocatalyst, reaches values of 630 mV. At a connected external resistor of 1 kΩ in the electric circuit, stable current densities of 170±10 mA m-2 are achieved. The electrical outputs depend on the anodic potential, reaching negative values of ca. -200 mV (vs. SHE). W. globosa produces an electrochemically active compound, acting as an electron shuttle. The polarization intensifies the W. globosa metabolism, expressed in a double increased glucose and starch content along with 1.82 times higher specific amylase activity of 70.0±2.8 U g-1 wet biomass in the organelle-enriched fractions of the explored as biocatalysts plants compared to the control. The results reveal that Wolffia globosa can be utilized as a biocatalyst in P-BFC for simultaneous electricity generation and increased carbohydrate and protein content.

Carbon-Nitrogen Ratios And Performance Of Nile Tilapia And Stinging Catfish In Biofloc Based Juvenile Rearing System.

A four-month indoor culture experiment was led to assess the impact of shifting C: N ratio on production, feed utilization, and physio-chemical parameters of biofloc-based juvenile rearing systems of Nile tilapia and stinging catfish with varying carbon-nitrogen proportions (C/N). The experiment contained different C: N ratios with every three replicates of 5:1, 10:1, 15:1, and 20:1 along with control. The outcomes indicate that the C/N ratio of 15: 1 combined with minute water exchange is ideal for enhanced survival and growth. After the feeding trial, a significant increase (p&lt;0.01) of 55.8% was observed in specific amylase activity in the C: N ratio 5: 1 in hepatopancreas, but no significant differences (p&gt;0.05) were observed in amylase activity in the gut as compared to control. Whereas, a significant increase (p&lt;0.01) of 84.3 and 82.3% was observed in the protease activity in the C: N ratio 5: 1 respectively in hepatopancreas and gut.

Dietary mixed Bacillus strains promoted the growth indices, enzymatic profile, intestinal immunity, and liver and intestinal histomorphology of Nile tilapia, Oreochromis niloticus

In the current investigation, a 4-week feeding trial was carried out to study the special effects of the dietary probiotic, Sanolife® PRO-F (a combination of Bacillus subtilis 3.25 × 109 CFU/g, Bacillus licheniformis 3.50 × 109 CFU/g, and Bacillus pumilus 3.25 × 109 CFU/g) supplementation on growth performance, serum biochemical immune parameters, intestinal digestive enzymes activities, antioxidants assay, and the expression of pro-inflammatory cytokines and antioxidant-related genes with a specific reference to intestinal histomorphometry of Nile tilapia, Oreochromis niloticus, which fed with Sanolife® PRO-F at 0 (B0), 0.5 (B0.5) and 1 (B1) g kg−1 diet, respectively. At the end of the feeding trial, the achieved results revealed that Bacillus strains probiotic supplementation significantly improved the growth performance including final body weight (FBW), weight gain (WG), specific growth rate (SGR), and feed utilization when matched to the control group (p < 0.05). Concerning serum biochemical parameters, there was a significant reduction in the serum cholesterol and triglyceride levels in fish-fed Bacillus strains (p < 0.01). Serum lysozyme activity showed greater values in the case of the B0.5 and B1 groups (p < 0.01) compared with the control. No changes were estimated in the levels of glucose, hepatic (alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and renal biomarkers (Urea, Creatinine, and Uric acid) in the serum of fish-fed B0.5 and B1 diets. Additionally, the specific activities of protease, amylase, and lipase enzymes were significantly increased upon Bacillus strains՚s incorporation in O. niloticus diets. As well, the antioxidant capacity of catalase (CAT) and superoxide dismutase (SOD) enzymes in the liver and spleen were significantly increased with diminished malondialdehyde (MDA) levels. Correspondingly, the mRNA expression of the antioxidant glutathione peroxidase (GPx) enzyme in the intestinal tissue was notably increased in the control group. The length of intestinal villi, absorptive epithelium, and goblet cell counts were greater in O. niloticus fed on Bacillus strains diets. Given the obtained results, the dietary supplementation of Sanolife® PRO-F to Nile tilapia, O. niloticus at 0.5 g kg 1 and 1 g kg−1 diet can recover the growth, feed utilization, and health condition with the safety of Sanolife® PRO-F probiotic supplementation on liver and kidney function.

Substitution of microalgae with microcapsule diet for two bivalve species, manila clam Ruditapes philippinarum and razor clam Sinonovacula constricta

In this study, a microcapsule diet was produced by spray-drying. Then, the filtration rate (FR) and ingestion rate (IR) of manila clam Ruditapes philippinarum were determined in relation to feeding on the microcapsule and microalgal Chaetoceros muelleri diets. Finally, two feeding experiments were conducted to evaluate the effects of increasing substitution of C. muelleri by the microcapsule on the survival rates, growth performances, biochemical compositions, and specific activities of digestive enzymes of two clams, R. philippinarum and razor clam Sinonovacula constricta. In experiment 1, the replacement of C. muelleri with the microcapsule was evaluated at three substitution levels (0%, 50%, and 100%) with R. philippinarum. In experiment 2, the replacement was evaluated at five substitution levels (0%, 25%, 50%, 75%, and 100%) with S. constricta. Results showed that the FR and IR of R. philippinarum in the microcapsule suspension were (4.07 ± 0.19) mL clam−1 min−1 and (6.36 ± 0.19) × 104 microcapsules clam−1 min−1, respectively. In experiment 1 and 2, no significant difference in survival rate of R. philippinarum or S. constricta was observed between different groups. The partial replacement of C. muelleri (25–50%) by the microcapsule diet did not significantly reduce the growth rates of these clams, while higher replacement (50–100%) did. The high-level microcapsule diet led to higher carbohydrate content when compared with high-level C. muelleri diet. In experiment 1, no significant difference in specific activity of amylase or lipase of R. philippinarum was observed between the 50% and 0% microcapsule groups. Meanwhile, no significant difference in specific activity of protease or lipase of S. constricta was observed between the 50% and 0% microcapsule groups in experiment 2. Our result suggested that the microcapsule was effective as a partial replacement of C. muelleri at up to 25–50% of dry weight of C. muelleri in clams.

The effect of hydrothermal processing on the performance of broiler chicks fed corn or sorghum-based diets

This study aimed to evaluate the effect of hydrothermal processing method on growth performance, digestive organ morphometry, activity of pancreatic amylase and lipase, plasma glucose and insulin concentration of broiler chicks fed post-hatching diets containing different carbohydrate sources (corn or sorghum). The experiment was carried out in a completely randomised design following a 2 × 2 factorial arrangement (factor 1: pelleting or extrusion processing; factor 2: corn or sorghum) with six replicates of 30 chicks each. Chicks were fed the diets in transport boxes for 24 h after hatch (post-hatch phase). After the post-hatch phase, all the chicks were housed and fed the same pre-starter diet. The response parameters were evaluated after 24 h and at seven days of age. The data were subjected to two-way ANOVA and the means compared by the Tukey post-hoc test (5%). After 24 h, chicks fed pelleted post-hatch diets showed a lower weight loss. Chicks fed diets containing sorghum had improved absorption of nutrients from yolk sac denoted by the reduced yolk sac weight. Broiler chicks fed extruded corn-based diets showed higher specific amylase activity (P < 0.001) and lower glucose concentration at 24 h after hatching (P < 0.001) while at seven days of age they showed the worst feed conversion rate (FCR) (P = 0.002). No difference on FCR was observed among the other groups (P> 0.05). Hydrothermal processing method nor carbohydrate source affected digestive organ weight of broiler chicks (P > 0.05). Broiler chicks fed extruded sorghum-based diets showed increased blood glucose levels in the post-hatch phase while the animals fed pelleted corn-based diets showed improved FCR during pre-initial phase.

Variations in digestive enzyme activity during larval development of cultured Pacific red snapperLutjanus peru

In the present study, the digestive enzyme activity during larval development in L. peru reared under intensive culture conditions was evaluated. The results revealed that L. peru larvae have the necessary enzymes to digest proteins, lipids and carbohydrates when nutritional reserves have been depleted at the onset of the exogenous feeding at 3 days after hatching (DAH) or 78 degree-days (DD). The activities of the digestive enzymes follow patterns similar to those previously reported in other related species. As in other marine fish larvae, the amylase specific activity decreased during larval development of L. peru. At 25 DAH (650 DD), the specific activities of lipase, alkaline phosphatase and acid phosphatase declined, while the specific activities of pepsin, trypsin and chymotrypsin increased. In contrast, the individual activity of all enzymes steadily increased with development. The time required to reach the maximum activity varies, suggesting a relative importance of different digestive enzymes during the different developmental stages of the digestive tract. In our study, the highest activity was reached by amylase at Stage I and early Stage II (3–11 DAH or 78–286 DD), by lipase and both acid and alkaline phosphatases at the end of Stage II (18–22 DAH or 468–572 DD), and by trypsin, chymotrypsin and acid protease at Stage III (25 DAH or 650 DD). This study provides new data on the digestive physiology of larval L. peru that are particularly pertinent to early weaning and nutritional physiology, and that may be useful in the larval culture of this species.

α-amylase from white pitaya (Hylocereus undatus L.) peel: optimization of extraction using full factorial design

Introduction. Amylase is a significant enzyme with numerous commercial applications, which is largely used to convert starches into oligosaccharides. Extraction of amylase from plant by-products or cheap sources is cost-effective. Annually, pitaya fruit juice industry produces huge amounts of peels that could be utilized as an alternative source in enzyme production industry. The work aimed to examine and optimize extraction process.&#x0D; Study objects and methods. In this study, we investigated parameters of extraction to optimize the process, as well as activity of α-amylase from white pitaya fruit (Hylocereus undatus L.) peel. For this purpose, a two-level full factorial design was applied. Three variables, namely the pH of sodium phosphate buffer (X1, 4.5–7.5), mixing time (X2, 1–3 min), and a sample-to-buffer ratio (X3, 1:3–1:5), were used to identify significant effects and interactions within the samples.&#x0D; Results and discussion. The results demonstrated that the buffer pH had the most significant (P ≤ 0.05) effect on total amylase activity. Based on full factorial design analysis, we revealed the optimal conditions for amylase enzyme extraction ‒ pH of 6, mixing time of 2 min, and a sample-to-buffer ratio of 1:4. Lower and higher values influenced adversely on specific activity of amylase.&#x0D; Conclusion. Optimization increased the enzyme specific activity by a factor of 4.5. Thus, pitaya peel could be used in different industries as a rich natural α-amylase source.

Mixed feeding schedules switching between dietary crude protein levels for mono-sex male Nile tilapia (Oreochromis niloticus)

The optimal mixed feeding schedule for mono-sex male Nile tilapia (Oreochromis niloticus) was investigated in the current study. The fish (4.01 ± 0.02 g initial weight and 5.84 ± 0.04 cm initial length) were fed up to satiation with high protein (HP, 32.80 % protein on dry basis) and low protein (LP, 28.64 % protein on dry basis) diets in different schedules: alternately every other day (1HP/1 L P), alternately every other week (7HP/7 L P) and alternately every two weeks (14HP/14 L P), in comparison to continuously feeding by HP (positive control) or by LP (negative control) alone. At the end of eight weeks of trial, superior growth performance and feed utilization were observed in fish receiving HP, 1HP/1 L P and 7HP/7 L P relative to the remaining treatments. The specific activity of digestive enzymes (pepsin, trypsin, amylase, lipase, and activity ratio of amylase to trypsin) was modulated, indicating physiological responses for improving nutrient utilization due to the different feeding regimens. All fish mainly utilized carbohydrates rather than lipid and protein, or probably the protein-sparing effect was predominant, as indicated by the positive correlation between amylase specific activity and protein efficiency ratio (r = 0.681, P < 0.01), across five feeding schedules. There were no negative effects of mixed feeding schedules on flesh quality and carcass composition in any experimental group. However, based on economic analysis, fish receiving 1HP/1LP schedule had reduced cost of tilapia production relative to the other treatments. Therefore, the optimal feeding schedule for mono-sex male tilapia is 1HP/1LP, which should be used as a practical feeding guideline for mono-sex male Nile tilapia production.

Oral administration of Bacillus subtilis and Lactobacillus plantarum modulates the gut microbiota and increases the amylase activity of Nile tilapia (Oreochromis niloticus)

The aim of this research was to evaluate the possible positive effects of feeding Nile tilapia (Oreochromis niloticus) with a diet containing a commercial probiotic AQUA-PHOTO® [Lactobacillus plantarum (1.51 × 106 CFU g−1) and Bacillus subtilis (1.34 × 107 CFU g−1)] on digestive enzymes’ activity and gut microbiome profile. The experimental design was completely randomized, with two treatments [control and probiotic diets (0.08 g.100 g−1 of feed)] and six replicate tanks per group (n = 8 animals per experimental unit, mean weight 8.18 g ± 1.85 g). The 96 fish were distributed into 12 aquaria and fed with the probiotic and control diets for 7 days. After this period, intestine samples (anterior, middle, and posterior portions) were collected from two individuals per tank. The samples were analyzed for assessment of DGGE profile and digestive enzymes’ activity (amylase, alkaline protease, and alkaline phosphatase). The results were subjected to analysis of variance (ANOVA) and the means compared by t test (P < 0.05). The addition of B. subtilis and L. plantarum in the diets modulated the intestinal microbial biodiversity, more specifically the species richness and habitability index (P < 0.05). Besides, probiotic feeding also increased specific amylase activity in the anterior gut (P < 0.05). The other variables studied did not show any significant differences between treatments. The oral administration of B. subtilis and L. plantarum (AQUA-PHOTO®) modulates intestinal microbiota profile and increases the amylase enzymatic activity. Therefore, this measure may provide better utilization of carbohydrate sources in the diet, supplying energy for Nile tilapia growth.

Effect of Tungstate Administration on the Lipid Peroxidation and Antioxidant Parameters in Salivary Glands of STZ-Induced Diabetic Rats.

Sodium tungstate is an alternative to reduce hyperglycemia for the treatment of diabetes. In previous work, we showed that the administration of sodium tungstate increased the specific activity of salivary amylase in the parotid gland. Here, we investigated the effect of the administration of sodium tungstate on the lipid peroxidation and some antioxidant parameters in the submandibular (SM) and parotid (PA) salivary glands of streptozotocin (STZ)-induced diabetic rats. Thirty-two male Wistar rats were divided into four groups (n = 8, each): control (C), control treated with sodium tungstate (CT), diabetic (D), and diabetic treated with sodium tungstate (CT). Sodium tungstate (2mg/ml) was administered to the STZ-induced diabetic rats for 15days. Malondialdehyde (MDA), reduced (GSH) and oxidized (GSSG) glutathione, and blood glucose concentrations were quantified. In addition, superoxide dismutase (SOD) and catalase (CAT) activities were assessed. Results revealed that diabetes caused an increase in MDA concentration in both glands, a reduction in the SOD activity in SM, and an increase in catalase activity in PA glands. Administration of sodium tungstate reduced the blood glucose levels and normalized the SOD activity in the SM and MDA levels in both glands of the STZ-induced diabetic rats. Catalase activity was increased in PA glands of diabetic and tungstate-treated animals (p < 0.05). The GSH/GSSG ratio was increased in SM glands of tungstate-treated animals (p < 0.05). Overall, the reduction of hyperglycemia by sodium tungstate reduced lipid peroxidation and caused alterations in the antioxidant system in the salivary glands of STZ-induced diabetic rats.

Ontogenic Development of Digestive Enzymes in Mealworm Larvae (Tenebrio molitor) and Their Suitable Harvesting Time for Use as Fish Feed

Mealworm larvae (Tenebrio molitor) are edible insects consumed in feed and food. In the current study, the optimal harvesting time of mealworm larvae for use as aquafeed was investigated during the ages of 30–90 days after hatching (DAH). Development of digestive enzymes, proximate composition, and in vitro protein digestibility using digestive enzymes from African catfish (Clarias gariepinus) and Nile tilapia (Oreochromis niloticus), were used as criteria. The specific activities of pepsin and trypsin significantly decreased with age (p < 0.05) from the first harvesting time until 50 and 45 DAH, respectively, while steadiness in these enzyme activities was observed onwards. Chymotrypsin specific activity appeared constant across all harvesting times. The specific activity of amylase significantly decreased in the later stages of development, while cellulase exhibited a different pattern suggesting it has a major role in dietary fiber utilization relative to starch. Regarding proximate compositions of the mealworm larvae, the moisture and ash contents decreased significantly with age, while the protein content exhibited the opposite trend with the highest contents from 60 to 90 DAH. Crude lipid was generally fairly constant, but its lowest value was observed in the earliest stage. In vitro protein digestibility was not significantly different across all harvesting times for both fish species, except for the significantly decreased digestibility value at 65 DAH relative to 30 and 35 DAH for Nile tilapia. However, based on the economic benefits of time for growth increment and proximate chemical composition, approximately 60 DAH is proposed as suitable for harvesting mealworm larvae to be used in fish feed.

Purification of Amylase Produced by Thermophilic Bacillus sp. TS9

Amylases are the starch degrading enzymes obtained from diverse sources such as plants, animals and microorganisms including bacteria and fungi. But the microbial amylases are preferred over other sources. The thermophilic alpha amylase obtained from bacterial species has applications in many industries. Six thermophilic bacteria Microbacterium sp. TS1, Pseudomonas sp. TS2, Alishewanella sp.TS3, Rheinheimera sp. TS5, Bacillus sp. TS9 and halophilic Bacillus sp. HS7 were isolated from Shahdrah and Kheiwera regions of Pakistan and their 16s RNA identified through molecular techniques. All the isolates were screened for amylase quantitatively and qualitatively. The Thermophilic Bacillus sp. TS9, based on its higher production of amylase, was selected for purification and characterization. The bacteria produced clearance zone of 2.7cm in diameter on 1% starch supplemented agar plate and the maximum specific activity of 2.45U/mg was obtained after 72 hours incubation at 45° C and pH 8. The extracellular amylase was then purified by ammonium sulphate precipitation and gel permeation chromatography. The specific activity of amylase obtained from Bacillus sp. TS9 increased to 4.47U/mg (1.82 fold) through partial purification, and 15.92U/mg (6.48 fold) through column chromatography. The current Study points out a valuable approach to purifiy the amylase and consequently improves the activity of amylase which have numerous applications in many industries

Improvement of non-specific immunity, growth, and activity of digestive enzymes in Carassius auratus as a result of apple cider vinegar administration to diet.

This study was conducted to evaluate the effects of apple cider vinegar (ACV) administration on non-specific immunity of serum and skin mucus, growth indices, and activity of digestive enzymes (amylase, lipase, and protease) in Carassius auratus. For this purpose, 180 fish (weighing 7.35 ± 0.19g) were allocated to 4 treatment groups with 3 replications in a completely randomized design. Fish were fed for 105days using a basal diet supplemented with 0% (control), 1% (T 1), 2% (T 2), and 4% (T 3) ACV (contained 5% acetic acid). Results showed a significant increase in lysozyme activity, ACH50, and total immunoglobulin of skin mucus in fish fed with T2 diet (p < 0.05). Total immunoglobulin and lysozyme activity were significantly lower in the serum of fish fed with control diet than those fed with the mentioned treatment (p < 0.05). The highest value was observed in fish fed with T2 diet. Minimum (p < 0.05) complement activity (1.52 ± 0. 25Uml-1) was observed in fish fed with control diet. The mean of the final weights (17.35 ± 1.39g), daily growth (1.0 ± 0.01g), and specific growth rate (2.19 ± 0.14) was significantly higher in T3 diet group than the controls (p < 0.05). While the highest amylase-specific activity was observed in the controls (p < 0.05), there was a significant increase in specific activity of protease, lipase, and alkaline phosphatase in T2 diet group (p < 0.05). According to the results of this study, the inclusion of a limited quantity of ACV (4%) into the diet can improve immunity and growth parameters in C. auratus.

Effects of feeding frequency on growth, feed utilization, digestive enzyme activity and body composition of Litopenaeus vannamei in biofloc-based zero-exchange intensive systems

An eight-week feeding experiment was conducted to investigate the effects of daily feeding frequency on the growth, feed utilization, digestive enzyme activity and body composition of Litopenaeus vannamei juvenile reared in biofloc-based zero-exchange intensive culture systems. The experiment was carried out in twelve tanks with 800 L of biofloc-rich water. Juvenile shrimp (1.52 ± 0.37 g) were stocked into tanks at 240 shrimp tank−1 (300 ind m−3). Three feeding frequencies of three, six, twelve times were evenly set in the 24 h of a day for experimental groups of F3, F6, F12 respectively. Each group had four randomly assigned tanks, and the shrimp were cultured for eight weeks with the same daily ration based on the monitoring of feeding trays in F3 group. During the experiment, all the monitored water quality parameters were maintained within acceptable ranges for shrimp culture. At the end of the experiment, the shrimp survival rate was higher than 89.03% in all the three groups. Notably, with the increase of daily feeding frequency from three times to six and further to twelve, significant differences were found as follows: (1) the final weight, growth rate and yield of the shrimp increased; (2) the feed conversion rate decreased while the protein efficiency ratio and protein productive value increased; (3) the specific activities of protease and amylase in the stomach of the shrimp and the specific activity of lipase in the digestive gland increased; (4) the crude protein content of the whole body of the shrimp increased while the moisture content decreased. Taken together, these results demonstrate that daily feeding frequency can affect the growth, feed utilization, digestive enzyme activity and body composition of L. vannamei juvenile reared in biofloc-based zero-exchange intensive systems. Distributing a controlled ration of daily feed at frequent times during 24 h of a day is beneficial for the growth, feed utilization, nutrient digestion, and protein deposition of L. vannamei in biofloc-based systems under controlled conditions.