Protease Enzyme Activity Research Articles

Endophytes Producing Proteases from Custard Apple (Annona squamosa L.) Leaves

The cost of the proteolytic enzymes and their inability to remove “fine” hairs from the animal hide has been the main obstacles to the commercialization of an enzymatic dehairing procedure. Endophytic microbes that grow inside various plant tissues without causing tissue damage in the host plant are the important sources of bioactive compounds. They are rich in secondary metabolites and known to produce wide range of enzymes. Several endophytes showing different properties have been reported from Annona leaves and hence this study was performed to isolate endophytes having proteolytic properties. Endophytes from custard apple leaves were isolated and screened for proteolytic activity on casein agar plates. The protease enzyme activity of the promising isolates was determined using casein substrate and tyrosine release assay. Present study conducted on the bacterial endophytes from the Custard apple leaves showed that the plant-associated bacterial endophytes are a good reservoir of proteases. Two promising isolates were obtained on the casein agar plates. These two isolates C and D possessed 113U/ml and 102 U/ml enzyme activity respectively. The isolate C showed more dehairing capacity than isolate D. Purified forms of these enzymes can prove to be potential candidates in biotechnological applications.

Analysis of protease activity of melinjo (Gnetum gnemon L.) skin on the tenderness of buffalo meat

To enhance the tenderness of meat, it can be accomplished physically or chemically. In chemical way, the process can be accomplished using protease enzymes that can be obtained from fruit, the higher the protease enzyme activity, the softer the meat. In this experiment, the extract and juice of melinjo skin (Gnetum gnemon L) was used to examine the protease enzyme activity. Papaya (Carica papaya) and pineapple (Ananas comosus) were used as a comparison. The research was conducted to understand the influence of incubation time (t) and incubation temperature (To) towards the optimum activity characteristic of protease enzyme on the juice and the extract of melinjo skin, papaya and pineapple. The incubation time of juice and extract was from 0 to 90 minutes with incubation temperature of 37 C and incubation time at 20 minutes with incubation temperature range from 20 to 80C. The protease enzyme activity of juice and extract expand significantly (p0.05) in conjunction with the increase of incubation time and temperature. The research results revealed that the maximum activity of protease enzyme detected at incubation time of 90 minutes for melinjo juice and pineapple skin, and 10 minutes for papaya. The optimum incubation temperature of melinjo skin at 70 C, papaya at 60C and pineapple juice at 60C. Meanwhile, the maximum activity of protease enzyme from melinjo extract identified in the incubation time at 80 minutes, papaya at 90 minutes and pineapple 60 minutes, whereas the incubation temperature of melinjo skin juice at 60 C, papaya at 80 C and pineapple at 30C.

Clinical validation of an activity-based enzyme assay for early stage lung cancer.

8533 Background: The USPSTF guidelines recommend annual LDCT scans for 15.5 million adults with a heavy smoking history. While LDCT can reduce deaths by 20%, screening compliance remains low. A blood test with clinically useful, cost effective performance could improve compliance and access when integrated with the standard of care. We describe here a lyophilized nanosensor system for detecting protease enzyme activity in sera with clinically useful diagnostic activity in early stage lung cancer. We evaluated the performance of the assay by examination of prospectively collected sera for detection of cancer in high risk patients. Methods: Sera were obtained in multiple independent studies to include pathologically confirmed, treatment naive lung cancer patients and LDCT confirmed negative individuals. Protease activity was measured on 18 different nanosensors built with protease targets mainly selective for members of the Matrix Metalloproteinase and Cathepsin families. Lyophilized plates were incubated with serum and enzyme activity was measured indirectly as a continuous variable by a fluorescent plate reader. A machine learning modeling tool (Emerge) was used to detect signal associated with a cancer “fingerprint” of protease activity. The analysis stratified allocation into training and testing sets of 250 samples each and reserved a third out of sample validation set (250 samples) for reporting. Results: 750 clinical samples included 30% lung cancers, 63% males, 91% smokers, and an average age of 63 years (SD=9). Cancer cases were distributed across stages I (41%), II (17%), III (20%) and IV (20%) with 5% unknown. Histological classification included 59% adenocarcinoma, 31% squamous cell and 11% other subtypes. Using an Emerge model with only nanosensor activity and gender as inputs, we evolved a balanced algorithm. The algorithm can be further modified to favor sensitivity or specificity depending on the application by applying model weighting factors. We report the performance observed in the 250 out of sample validation set at three points on this spectrum (Table). Among Stage I cancer samples, the balanced algorithm had an accuracy of 90% (26/29). Conclusions: Current LDCT tools show low compliance. We demonstrate clinical validity of a cost effective tool to detect lung cancer in support of LDCT screening. Based on a simple blood sample, the current test may predict early stage lung cancer with an accuracy of 90%. The performance suggests applications in LDCT compliance, post LDCT management, and eventually screening. A clinically validated version of this technology is being evaluated as a triage tool for LDCT screening. [Table: see text]

Valorization of the insect waste as a source of dietary protein in replacing the fishmeal protein for the cage reared Pangasianodon hypophthalmus: An approach to search the alternate non-conventional feed resource of animal origin

A ninety days experiment was carried-out to evaluate the effect of dietary replacement of fishmeal (FM) (locally available dried non-defatted Coilia dussumieri V.) by graded inclusion levels of non-defatted non-mulberry Indian tropical tasar silkworm spent pupae (Antheraea mylitta D.) on growth performance, feed consumption, digestive enzyme response, body chemical composition, and intestinal cellular micro-morphological status of the reared striped catfish (Pangasianodon hypophthalmus S.). Five iso-nitrogenous (280 g protein kg-1) and iso-energic (19 MJ kg-1) extruded floating feeds were formulated by gradually replacing the FM with NDSWP (non-defatted silkworm pupae) at 0%, 25%, 50%, 75%, and 100% (on protein to protein basis) levels and the diets are designated as NDSWP0, NDSWP25, NDSWP50, NDSWP75, and NDSWP100, respectively. The contribution of calculated pupae crude protein was 0%, 4.75%, 9.50%, 14.25%, and 19% out of the total protein (28%) content in the respective diets. The experiment was executed in the floating net-cage located at the Maithon reservoir, India which is a field research station of ICAR-CIFRI, Barrackpore, Kolkata, India. The designated diets were randomly allocated to 10 numbers of experimental cages (each 5 ×5 ×3 m), in triplicates stocked with 2475 numbers (stocking density at 33 numbers per m3) of striped catfish in each replication and fed daily twice at 08.00 h and 16.00 h. The initial stocking size of the striped catfish fingerling was 16.56 ± 0.08 g. At the termination of the feeding experiment, the final body weight (g), individual weight gain (g), weight gained (%), feed conversion ratio (FCR), specific growth rate (SGR), and protein efficiency ratio (PER) found to be non-significantly different (p < 0.05) up to 50% protein replacement level (NDSWP50) in comparison to the control (NDSWP0). Among the biological indices, hepatosomatic index (HSI) exhibited a non-significant difference stretching to NDSWP50 treatment group with a distinct significant difference between NDSWP25 and NDSWP100 (p < 0.05), when, an inverse trend was recorded in relation to increasing pupae meal in the diets. Among the digestive enzymes, relatively higher protease enzyme activity was observed in the diet fed at NDSWP50 compared to the rest of the treatment groups, although, it was statistically non-significant (p > 0.05). Amylase and lipase enzyme activities recorded a significant difference among the treatment groups (p < 0.05). A higher amount of fish muscle crude protein was noticed in the NDSWP50 treated group than in the rest of the treatment groups. The lipid content of fish muscle indicated its higher content over the initial and exhibited an inverse relationship with moisture and ash content at the end of the experiment. Histo-morphology of gut tissue confirms the suitability of feeding pupae protein incorporated diet with the gradual replacement of fishmeal protein. The findings of the current feeding trial suggests that the inclusion of non-defatted non-mulberry silkworm pupae protein at 50% level of fishmeal protein substitution without compromising the growth performance, nutrient utilization, conversion of feed, and other biological indices, and economics of diet.

Responses of Soil C, N, and P Stoichiometrical Characteristics, Enzyme Activities and Microbes to Land Use Changes in Southwest China Karst

The present study aim is to elucidate the effect and influencing mechanism of land use change on soil C, N, and P stoichiometric characteristics, soil enzyme activity and the microbial community in the karst ecosystem of southwest China. The three typical successive evolution land use types of original forest land, slope farmland and shrub-grassland were selected as the study objects in the present study. Additionally, the change in the laws and relationships of soil, the C, N, and P stoichiometric characteristics, the five soil enzyme activities of urease, sucrose, alkaline phosphatase, amylase and protease, and soil microbial community during the land use evolution process were studied. Results showed that (1) during the evolution process of the three land use types, soil C, N, and P stoichiometric characteristics, enzyme activities and microbial PLFAs (phospholipid fatty acids) varied significantly or extremely significantly; (2) in the three land use types studied, there were significant or extremely significant correlations between soil C, N, and P stoichiometric characteristics, enzyme activities and microbial PLFAs; (3) the ecological project of returning farmland to woodland had remarkable ecological effects on increasing soil C and N sink, repairing soil microbial community and improving soil quality; (4) artificial afforestation should be used as the most important and preferential measure for karst vegetation restoration and reconstruction. The present results not only provided scientific bases for land sustainable utilization, vegetation restoration and reconstruction, but also had important value in reducing the release and increasing the sequestration of soil C and N in karst ecosystems of Southwest China.

Biodegradation Test of Polluted River Caused by Domestic Wastewater Using Indigenous Bacteria in the Way Tomu Watershed, Ambon City

Nowadays, the rivers are often used by residents around the river as the final disposal of domestic wastewater that causes the rivers to become polluted. Biodegradation is an alternative to wastewater treatment as an effort to solve water pollution which is often carried out using bacteria that have the potential to decomposers in the biodegradation process, especially indigenous bacteria. This study aims to identify and obtain isolates, combinations, and characteristics of the indigenous bacteria isolate that have the potential as a biodegradation agent for polluted river caused by domestic wastewater in the Way Tomu watershed, Ambon City. In this study, isolates of indigenous bacteria that were isolated and purified were tested for protease and amylase enzyme activity to select isolates to be used in the biodegradation process testing consisting of parameters pH, COD, and TSS as indicators of the biodegradation. Afterward, the isolates that have the best potential as biodegradation agents will be characterized and biochemical tests will be carried out to identify the general characteristics of these isolates. The results showed that the combination of Genus Aeromonas, Bacillus, and Pseudomonas as isolates of indigenous bacteria that has the best potential as an agent for the biodegradation of polluted river caused by domestic wastewater. The benefit of this research is as initial information and consideration for alternative treatment of polluted rivers caused by domestic wastewater using indigenous bacteria isolates as an effort to resolve river pollution, especially the rivers in Ambon City.

Screening of a Novel Fibrinolytic Enzyme-Producing Streptomyces from a Hyper-Arid Area and Optimization of Its Fibrinolytic Enzyme Production

Fibrinolytic enzymes are a kind of proteolytic enzymes that can hydrolyze fibrin and dissolve blood clots. They could be used as a therapeutic agent for treating thrombosis. It is important for the treatment of cardiovascular disease to find and develop new thrombolytic drugs. In order to explore new fibrinolytic enzymes, a strain named 214L-11 with protease and fibrinolytic enzyme activity, which was isolated from the Flaming Mountain of Xinjiang Province, was screened using the skimmed milk plate, the blood powder agarose plate and the fibrin plate methods. Phylogenetic analyses showed that strain 214L-11 shared the highest similarity with Streptomyces fumanus NBRC 13042T (98.88%), which indicated that it represented a potential novel species in the Streptomyces genus. The fibrinolytic enzyme produced by 214L-11 displayed thrombolytic and anticoagulant activities, and it could degrade a single specific protein in the thrombus, thereby destroying the thrombus structure. The fermentation medium optimized through response surface methodology was 15 g/L soluble starch, g/L KNO3 0.58, 0.43 g/L peptone, 0.01 g/L FeSO4·7H2O, 0.5 g/L MgSO4·7H2O, 0.2 g/L Mn2+, 0.5 g/L NaCl and 1 L distilled water, pH 8, and the maximum amount of fibrinolytic enzyme produced by strain 214L-11 in the optimal fermentation medium was 1255.3 FU/mL. Overall, the fibrinolytic enzyme-producing strain was screened from the Flaming Mountain of Xinjiang for the first time, which provided a basis for further research and the development of new efficient and safe hemolytic drugs.

Enhancement of alkaline protease production in recombinant Bacillus licheniformis by response surface methodology

Alkaline protease is widely used in the food, detergent, and pharmaceutical industries because of its comparatively great hydrolysis ability and alkali tolerance. To improve the ability of the recombinant Bacillus licheniformis to produce alkaline protease, single-factor experiments and response surface methodology (RSM) were utilized to determine and develop optimal culture conditions. The results showed that three factors (corn starch content, soybean meal content, and initial medium pH) had significant effects on alkaline protease production (P < 0.05), as determined through the Plackett‒Burman design. The maximum enzyme activity was observed with an optimal medium composition by central composite design (CCD): corn starch, 92.3 g/L; soybean meal, 35.8 g/L; and initial medium pH, 9.58. Under these optimum conditions, the alkaline protease activity of strain BL10::aprE was 15,435.1 U/mL, 82% higher than that in the initial fermentation medium. To further investigate the application of the optimum fermentation medium, the overexpressed strain BL10::aprE/pHYaprE was cultured using the optimized medium to achieve an enzyme activity of 39,233.6 U/mL. The present study achieved the highest enzyme activity of alkaline protease by B. licheniformis at the shake-flask fermentation level, which has important application value for large-scale production.Graphical

Inhibition of protease activity and anti‐quorum sensing of the potential fraction of ethanolic extract from Sansevieria trifasciata Prain leaves against Pseudomonas aeruginosa

Sansevieria trifasciata is a plant that is commonly utilized in traditional medicine. The leaves of S. trifasciata show antibacterial properties against Pseudomonas aeruginosa. This bacterium is an opportunistic pathogen that can cause serious illness in humans and produce a variety of virulence factors responsible for bacterial pathogenesis with quorum sensing (QS) systems that mediate intracellular communication. Bacteria produce protease through a QS mechanism in which they express signaling molecules to become pathogens. Proteases are extracellular enzymes required for successful infection that mediate biofilm spread through QS and regulate a variety of cellular and physiological functions. This research aimed to evaluate the protease, and anti‐QS activities of the ethanolic extract from S. trifasciata leaves against P. aeruginosa and the expression of QS genes. An azocasein test was used to determine the protease activity in qualitative and quantitative methods. Using real‐time quantitative polymerase chain reaction, a study was conducted to investigate the effect of ethanolic extract from S. trifasciata leaves on selected QS‐regulatory genes at the transcriptional level. The results showed that the potential ethanolic extract from S. trifasciata leaves inhibited the protease enzyme activity by as much as 77.1%. The potential ethanolic extract from S. trifasciata leaves decreased the expressions of lasA, lasB, lasI, lasR, rhlI, and rhlR with 2‐ΔΔCt values of 0.81, 0.93, 0.76, 0.97, 0.90, and 0.55 respectively.

Endophytic bacteria as biological agents to control fusarium wilt disease and promote tomato plant growth

Plant endophytic bacteria are symbiotic bacteria that live in plant tissues and may play a role in disease control and/or plant growth promotion. In this study, six plant endophytic bacterial isolates, Arthrobacter sp. AM08, Pseudomonas aeruginosa AJ14, P. mosselii AB06, Bacillus cereus AP12, B. thuringiensis AK08 and Serratia marcescens AS09, were tested for their ability to control Fusarium oxysporum f. sp. lycopersici (FOL) and to promote the growth of tomato plant. The isolates were evaluated for their ability to produce hydrolytic enzymes (cellulase, protease and chitinase), hydrogen cyanide (HCN), indole 3-acetic acid (IAA), 1-aminocyclopropane 1-carboxylic acid (ACC) deaminase, and siderophores. The activity of cellulase, protease and chitinase enzymes was detected in all the isolates studied, whereas the highest HCN activity was observed in P. aeruginosa. The activity of IAA, ACC deaminase, and siderophore was also observed in all isolates, with B. cereus, P. mosselii, and S. marcescens being the highest producers of IAA and B. thuringiensis being the highest producer of siderophores. All isolates produced ACC deaminase at almost the same level. Application of the isolates to tomato seeds prolonged FOL incubation time, reduced disease incidence, and shortened xylem discoloration length compared to the controls, confirming the ability of the isolates to control FOL. In addition, all tested isolated showed plant growth promoting activity, as indicated by increased plant height and root length. The study showed that the endophytic bacteria are capable of controlling FOL and promoting the growth of tomato plant, revealing their potential to be developed as biocontrol agents.

Combined Effects of Dietary Probiotic Lactobacillus sp. and Prebiotic Glycyrrhizic Acid on Growth Performance, Feed Utilization and Digestive Enzymes Activities of Nile Tilapia (Oreochromis niloticus) Juveniles

The present study investigated the effects of dietary commercial probiotic Lactobacillus sp. and commercial prebiotic glycyrrhizic acid on the growth performance, feed utilization and digestive enzymes activities of Nile tilapia. Seven diets with or without probiotics and prebiotics supple-mentation namely Control (without probiotics and prebiotics), P10, P20 and P30 (Control + Pro-aqua) and V2, V4 and V6 (Control +Viusid) were fed to juvenile Nile tilapia (5.22±0.05 g) for 60 days in triplicate tanks (30 fish per tank). All fish were fed ad libitum three times a day for 60 days. At the end of the experiment, the weight gain and specific growth rate of the fish fed with probiotic content group was found to be higher than the other groups (P&lt;0.05). In the experiment, there was no change in the nutritional value of tilapia fed with a diet containing all feeding groups (P&gt;0.05). On the other hand, significant changes were observed in alkaline and acid protease enzyme activities depending on the days (P&lt;0.05). Especially, after the first 15-day period of the experiments, increases in both supplemented groups enzyme activities were determined. The increase in enzyme activity in the probiotic supplemented groups showed higher activity than the prebiotic administered groups (P&lt;0.05). It can be concluded that probiotic can act as a growth promoter and increase digestive enzymes activity in tilapia.

Detection of the Enzymes and Toxins Produced by the Pathogenic Fungi that Cause Chias Pollen Disease on Different Date Palm Cultivars in Iraq

Mohamed, Kh.A. and M.A. Alfahd. 2023. Detection of the Enzymes and Toxins Produced by the Pathogenic Fungi that Cause Chias Pollen Disease on Different Date Palm Cultivars in Iraq. Arab Journal of Plant Protection, 41(1): 65-70. https://doi.org/10.22268/AJPP-41.1.065070 This study aimed to determine the exo-enzyme activity of some inflorescence-rot causing fungi that were isolated from different date palm cultivars such as Mauginiella scaettae, Fusarium solani, Fusarium oxysporium and Alternaria radicina and their ability to produce protease and cellulase enzymes on Czapek dox (CD) liquid media supplemented with carboxy methyl cellulose (CMC), as well as their ability to produce Fumonisin B1 toxin using the enzyme linked immunoassay assay (ELISA). The results obtained showed a discrepancy in the amount of enzymes and toxins produced by these pathogens. The fungus F. oxysporum produced the highest cellulase enzyme activity, which amounted to 1.1933 units/ml, whereas Alternaria radicina produced the highest protease enzyme activity which amounted to 50,964 units/ml. The pathogen M. scaettae produced the highest toxin concentration of 38.465 µg/kg, whereas the pathogen Fusarium solani did not produce this toxin. Keywords: Mauginiella. Scaettae, enzymes, fumonisin B1, toxins.

Evaluation of virulence factors and azole resistance mechanisms of Candida tropicalis isolates from head and neck cancer patients with OPC.

Candida tropicalis is one of the major non-albicans species causing nosocomial infection. There is limited data about mechanisms of azole-resistance and virulence factors of Candida tropicalis. This study was designed to investigate molecular mechanism of azole-resistance and major virulence factors of C. tropicalis isolated from oropharyngeal candidiasis in head and neck cancer patients. After collecting 38 C. tropicalis clinical isolates, antifungal susceptibility pattern and the expression levels of ERG11, CDR1, CDR2 and MDR1 were evaluated. Moreover, proteinase and phospholipase activity and biofilm formation of the isolates were investigated as virulence factors. We detected fluconazole resistance in 7 C. tropicalis isolates. The expression levels of CDR1, ERG11 and MDR1 were increased respectively. Protease activity and biofilm formation were seen in all isolates. Five isolates did not exhibit phospholipase activity. Taken together, the overexpressions of ERG11, CDR1 and MDR1 genes were found in fluconazole resistant C. tropicalis, isolated from oropharyngeal candidiasis patients. Also, voriconazole was an effective antifungal against C. tropicalis isolates. The observed high protease enzyme activity and biofilm formation suggested strong pathogenicity of these isolates.

Effects of dietary Bacillus on foraging behavior, food consumption, digestive enzyme activity, and defecation outputs of the sea cucumber Apostichopus japonicus at low temperature: New insights into overwintering management

Low efficiency is one of the most serious problems of sea cucumber (Apostichopus japonicus) seed production in winter. Probiotics as dietary supplements have the potential to address this problem. The aim of this study was to investigate the effects of the application of dietary Bacillus amyloliquefaciens and B. methylotrophicus on foraging behaviors, food consumption, digestive enzyme activity, and defecation outputs of small A. japonicus that were cultured in sea water at 5 °C for 12 days. We found that sea cucumbers supplemented with Bacillus showed significantly longer foraging distance (N = 6, P < 0.001), higher foraging success rate (N = 6, P = 0.016), shorter foraging time (N = 6, P = 0.006), and faster foraging speed (N = 6, P < 0.001), compared to the control group. In addition, food consumption (N = 9, P < 0.001), amylase (N = 3, P = 0.039) and protease enzyme (N = 3, P = 0.025) activities, and defecation outputs (N = 9, P = 0.04) of sea cucumbers fed with a diet supplemented with Bacillus were significantly higher than those of the control group. These results indicate that dietary Bacillus has great potential to increase the aquaculture productivity of sea cucumbers in winter. It is advisable to be an environmentally friendly solution to resolve the overwintering problems in A. japonicus aquaculture. The present study further enriches our understanding of the potential role of Bacillus and provides valuable information for its application at low temperature and new insights into the overwintering management for A. japonicus aquaculture.

Ameliorative role of dietary acidifier potassium formate on growth metrics, blood chemistry, gut health and well-being indices of rohu, Labeo rohita fingerlings.

Organic acids and their derivatives have been attributed to growth and well-being improvement in fish when supplemented in their diets. Therefore, this study was conducted to evaluate the ameliorative role of potassium formate (PF) in rohu Labeo rohita fingerlings. A total of 240 healthy rohu fingerlings (9.0 ± 0.5 g ± SE) were randomly divided into four equal groups in triplicates. Fish were fed with isonitrogenous feeds: PF10 (10 g PF/kg), PF20 (20 g PF/kg) and PF30 (30 g PF/kg). Feed without PF supplementation served as control. The results indicated that the specific growth rate (SGR) and feed conversion ratio (FCR) were significantly (p<0.05) higher in PF10. Total serum globulin content was found significantly (p<0.05) elevated in PF10 after the bacterial challenge. Non-specific lysozyme activity was significantly higher (p<0.05) after the challenge. The digestive protease enzyme activity was significantly (p<0.05) improved in PF10 treatment. Additionally, the digestive morphology of the treated fish was seen to be improved. Greater villus area, increased villus number, reduced lumen space in the hindgut, reduced vacuolation in mucosal folds and proliferation of goblet cells-like changes were observed in the PF-supplemented fish. Significantly (p<0.05), a higher relative percentage of survival (RPS) was observed in PF10 and PF20 treatments. The study revealed that the dietary supplementation of rohu fingerlings with lower levels of potassium formate could enhance the nutritional efficiency and physiological activities of rohu fingerlings. This study serves as a baseline for future research on the application of formic acid derivatives and other acidifiers in carp culture.

Evaluation of Different Transition Periods in Feeding Live Feed for Tiger Shovelnose Catfish (Pseudoplatystoma punctifer, Castelnau 1855) Larvae

The production of tiger shovelnose catfish (TSN) is limited by the very low growth during feeding transition in phase larvae. This research aims to evaluate the difference in feed transition period from nauplii Artemia sp. to Tubifex sp. on the growth and activity of digestive enzymes of TSN larvae. TSN larvae 1 dph (day post hatching) with total length of 4.05±0.16 mm and weight of 4.18±0.67 mg were used in this study. Nine aquariums with 10 L of water were stocked with larvae at a density 30 larvae/L. This study consisted of three treatments of different feed transition time in triplicates i.e. transition at 9 dph (P1), 10 dph (P2) and 11 dph (P3). The result showed that the transitional on 11 dph (P3) recorded the highest total length (36.9±0.56 mm), total weight (242.5±2.4 mg), daily length growth rate (13.43±0.81 %.mm/day), daily weight growth rate (25.4±0.06 %.mg/day), survival rate (81.7±3.1%), and protease enzyme activity (0.222±0.019 IU/mL) compared to 10 dph (P2) and 9 dph (P1). The transition period of 11 days is the mostappropriate time to change the feed for nauplii Artemia sp. to Tubifex sp. in TSN larvae because it produces the best growth and digestive enzyme activity values.

Understanding the impact of halogen functional group (Br, Cl, F, OH) in amprenavir ligand of the HIV protease

We focused our attention towards the most dreadful disease that threatens the mankind of 20th century - Acquired immunodeficiency syndrome (AIDS), caused through the human immunodeficiency virus (HIV) and a sexually transmitted infection (STI). In this study, our foremost interest was to identify the potency and stability of HIV ligand- Amprenavir (APV) and its modelled functional group (Br, Cl, F, CF3, CH3, NH2) ligands through halogen and hydrogen bond contact, which will have a clear portrait on the structure activity of protein ligand interactions. This will assist chemist in synthesizing novel APV ligands, which are expected to inhibit the activity of HIV-1 protease enzyme. The binding strength of Amprenavir ligand with interacting hinge region amino acid side chains: Isoleucine (ILE 147, 150, 184), Valine (VAL 82), Alanine (ALA 28), Aspartic acid (25, 30, 125, 130) and Glycine (GLY 127, 149) were understood through interaction energy calculations at HF, B3LYP, M052X, MP2 level of theories for different basis set (6-311 G**, LANL2DZ). The present work will reveal an understandable picture about the halogen and hydrogen bond interaction that grip the contact of ligand and amino acids in the hinge region. Overall the Halogen atom (Br, Cl, F) functional groups improved the binding strength of APV in HIV protease; which provide a new novel path for the functional group preference on the ligand that enclose perfectly with the amino acid in the hinge region. Communicated by Ramaswamy H. Sarma

The effect of different dosage probiotic Bacillus cereus in fish diets on the growth and enzyme activities of coral trout grouper juvenile, Plectropomus leopardus

Coral trout grouper (Plectropomus leopardus) is one of the economically important marine fish. The feed nutrients and probiotics influence the digestive system of fish. This research aims to get an optimal dosage of the probiotic Bacillus cereus on the diet for enhanced growth and enzyme activity of coral trout grouper juveniles. The experiment was conducted with different treatments with four dosages of probiotics in the diet: 0%, 0.5%, 1.0, % and 1.5%, and repeated four times. The diet was formulated with 48.32%-49.25% protein and 11.97%-12.98% lipid—twelve juveniles of coral trout grouper with an average weight of 5.7±0,3 g and length of 7.3±0,3. The fish were reared in 30 L of 16 polycarbonate tanks with a flow-through system. The research was carried out for eight weeks. The Fish were fed two times a day. The observed parameters were carried out for specific growth rate, survival rate, feed efficiency, viability of bacteria in diet, and enzyme activity. The results showed that the probiotics Bacillus cereus diet increased growth, feed efficiency, viability of probiotic bacteria, protease enzyme activity, and lipase enzyme activity in the intestine. The dosage of probiotics 1.5% in feed showed better results than other diets (P &lt;0.05).

Body composition, growth performance and enzyme activities of Labeo rohita fed different commercial fish feeds.

We have evaluated the effects of different fish feeds on the body composition, growth, and enzyme activities of Labeo rohita (Rohu). In total, 240 fishes between the average weights of 24.77±2.15g were studied. The treatments were applied in a completely randomized design, with 4 treatments of 60 fishes each. Treatments consisted of four different fish feeds [Oryza (T1), AMG (T2), Aqua (T3), and Supreme (T4)]. Body composition, growth performance, and enzyme activities were evaluated. There was a significant variation in performance of fishes fed with different type of feed; as fishes having Oryza feed showed the highest weight gain, specific growth rate (SGR), and best feed conversion ratio (FCR) as compared to other groups that were considered to be significant (P ≤ 0.05). High net weight gain was obtained in T4 when compared with T2 and T3. FCR value of T4 was less than T1 but higher than T2, T3 and T2, which showed the lowest values. The specific growth rate was recorded as average in T4, but T2 led a high SGR than T3. Similarly, crude protein level and digestive enzymes activity was recorded significantly highest in fed with Oryza (T1) as compared to AMG (T2), Aqua (T3), and Supreme (T4). Water quality parameters were recorded significant in all treatments except pH and DO of treatment (T1), significantly different from other treatments. It was concluded that Rohu (Labeo rohita) could show a promising growth rate and protease enzyme activity when fed with the Oryza feed of 25% protein.

Chromium supplemented carbohydrate diets for Cirrhinus mrigala: effects on body composition, gut enzyme activity and hematological parameters.

A ninety days nutritional trial was directed to explore the effects of dietary chromium on body composition, gut enzyme activity and physiological status of Cirrhinus mrigala by using G & NG corn. Six experimental diets were prepared by using different levels of chromium chloride hexahydrate (0, 0.2, 0.4 mg/kg, each with G & NG corn). For this experimental trial, 480 fingerlings, irrespective of sex were distributed in six aquariums each with replicate. Results revealed that gelatinized corn along with increasing level of Cr2Cl3.6H2O have a positive impact upon body composition of fish. Hematology was positively correlated with chromium chloride hexahydrate supplementation in gelatinized corn. Amylase gut enzyme also showed significant (P<0.05) increase in group fed with chromium chloride hexahydrate supplemented diet (G corn). However, corn with chromium chloride hexahydrate supplementation did not revealed any significant impact on gut protease enzyme activity. From these results it can be concluded that both chromium chloride hexahydrate and gelatinized corn in fish feed are very beneficial to improve body composition, enzymes activity and physiological health status of fish.