Days Of Culture Research Articles

Effects of background color on survival, growth, and shell coloration of juvenile Chinese mitten crab (Eriocheir sinensis)

Background color is a crucial factor influencing the growth performance and feed utilization in crustaceans. However, little is known about its impacts on the culture performance of Chinese mitten crab (Eriocheir sinensis). In this study, we examined the impacts of six different background colors (white-W, black-BK, green-G, red-R, yellow-Y, and blue-BL) on growth, inter-molt period, and coloration and total carotenoids content of carapace of juvenile E. sinensis. The culture experiment comprised two trials: a 68-day individual culture, and a 30-day group culture. Individual culture results: No significant effects of background color were found on weight gain rate (WGR), specific growth rate (SGR), molting interval, carapace length and width, and survival rate (SR) of the juvenile crabs (P > 0.05). However, during the second molting cycle, the BL group exhibited the highest WGR, and the G group showed the lowest hepatopancreas index (HSI). Meanwhile, markedly lower feed conversion ratio (FCR) was obtained for the W group compared to the G and BK groups. Group culture results: Significantly higher SR was recorded for the BK group, and the highest limb loss rate was detected for Y group indicating the significant effects of background color on survival and aggressiveness of juvenile E. sinensis. Moreover, background color impacted the carapace coloration indices where the W, BK and Y groups showed the highest brightness (L*), redness (a*), and yellowness (b*) values, respectively. Furthermore, correlation analysis revealed a positive linear relationship between the L* value and background color (y =0.1638x+27.961, R2=0.613). In conclusion, our results demonstrated that background color significantly affects culture performance and carapace color. Black background color was shown to enhance the survival rate and reduce the limb amputation rate under group culture condition. These results provide new insights on the optimization of farming technology for juvenile E. sinensis.

Reusing biofloc-culture water and microbubble aeration for culturing the white-leg shrimp Litopenaeus vannamei

This study investigated the effects of reusing biofloc-culture water for culturing the white-leg shrimp Litopenaeus vannamei. Experiments were conducted for two continuous cycles without water exchange for 30 days during the nursery stage. The studies were performed with two different aeration systems, namely microbubbles (MB) and large air bubbles (LB). Water quality parameters such as dissolved oxygen (DO), temperature, pH, salinity, alkalinity, total ammonia nitrogen (TAN), nitrite, nitrate, settleable solids (SS), and total suspended solids (TSS) were recorded throughout the culture days. Also, comparisons were performed on parameters of the shrimp growth, i.e., body weight and length, feed conversion ratio (FCR), and specific growth rates (SGR) for the 30-day culture for Cycles 1 and 2. Cycle 2 showed no deterioration in water quality and no significant difference in growth performance compared to Cycle 1 for either aeration method (MB and LB). However, when comparing between aeration methods, MB aeration significantly improved the DO of the water and accelerated the conversion of TAN to nitrate. Shrimps in the MB aeration system were significantly larger (by 39%) with a lower FCR value (reduced by 30%) than in the LB aeration system. Harmful bacteria from the Vibro group were detected. However, they occurred at a minimum level in both cycles and aeration types. Overall, the biofloc-culture water might be reused for the subsequent cycle, while the MB aeration might promote the growth of biofloc and L. vannamei.

Production of Cheese and Ice Cream Enriched With Biomass and Supernatant of Spirulina platensis With Emphasis on Organoleptic and Nutritional Properties

Background: Spirulina platensis contains natural pigments along with phenolic and flavonoid compounds that may be excreted to the supernatant in addition to biomass during culture. Objectives: We prepared enriched cheese and ice cream using biomass and supernatant of S. platensis microalgae extract. We aimed to evaluate these algae’s organoleptic and nutritional properties. Methods: After preparing a 30-day culture of Spirulina, different concentrations of its biomass and supernatant extract were prepared to enrich cheese and ice cream. In the next step, the physicochemical and antioxidant properties of the products were measured by FRAP (ferric reducing antioxidant power) and DPPH (2,2-diphenyl 1-picryl hydroxyl) methods. Expert evaluators performed the sensory analysis according to the Iranian national standard method in terms of color, odor, taste, texture, and general acceptance on a scale of 0 to 5. Finally, statistical analysis of the data obtained from each experiment was performed with a one-way analysis of variance three times using SPSS software, version 24. Results: The results showed that the content of protein, fat, ash, and biomass was higher in enriched foods. However, in enriched ice creams, the content of protein, fat, sugar, and aeration rate increased significantly compared to the supernatant. In addition, cheese and ice cream fortified with supernatant had significantly greater antioxidant activity than biomass. The results of the hedonic test showed that with increasing concentrations of these agents in fortified cheeses and ice creams, the level of satisfaction in odor, taste, color, texture, and general acceptance factors was increased. Conclusion: The study results showed that adding biomass and supernatant of S. platensis to ice cream and cheese increased the nutritional value and improved the taste of these foods. Because these substances play an essential role in children’s diet, this microorganism can be used to combat malnutrition and a diet without micronutrients.

Use of Antipseudomonal Antibiotics is Not Associated With Lower Rates of Postoperative Drainage Procedures or More Favorable Culture Profiles in Children With Complicated Appendicitis: Results From a Multicenter Regional Research Consortium.

To compare rates of postoperative drainage and culture profiles in children with complicated appendicitis treated with the 2 most common antibiotic regimens with and without antipseudomonal activity [piperacillin-tazobactam (PT) and ceftriaxone with metronidazole (CM)]. Variation in the use of antipseudomonal antibiotics has been driven by a paucity of multicenter data reporting clinically relevant, culture-based outcomes. A retrospective cohort study of patients with complicated appendicitis (7/2015-6/2020) using NSQIP-Pediatric data from 15 hospitals participating in a regional research consortium. Operative report details, antibiotic utilization, and culture data were obtained through supplemental chart review. Rates of 30-day postoperative drainage and organism-specific culture positivity were compared between groups using mixed-effects regression to adjust for clustering after propensity matching on measures of disease severity. In all, 1002 children met the criteria for matching (58.9% received CM and 41.1% received PT). In the matched sample of 778 patients, children treated with PT had similar rates of drainage overall [PT: 11.8%, CM: 12.1%; odds ratio (OR): 1.44 (OR: 0.71-2.94)] and higher rates of drainage associated with the growth of any organism [PT: 7.7%, CM: 4.6%; OR: 2.41 (95% CI: 1.08-5.39)] and Escherichia coli [PT: 4.6%, CM: 1.8%; OR: 3.42 (95% CI: 1.07-10.92)] compared to treatment with CM. Rates were similar between groups for drainage associated with multiple organisms [PT: 2.6%, CM: 1.5%; OR: 3.81 (95% CI: 0.96-15.08)] and Pseudomonas [PT: 1.0%, CM: 1.3%; OR: 3.42 (95% CI: 0.55-21.28)]. The use of antipseudomonal antibiotics is not associated with lower rates of postoperative drainage procedures or more favorable culture profiles in children with complicated appendicitis.

Mesocosm experimental study on sustainable riparian restoration using sediment-modified planting eco-concrete

The continued deterioration of riparian ecosystems is a worldwide concern, which can lead to soil erosion, plant degradation, biodiversity loss, and water quality decline. Here, taking into account waste resource utilization and eco-environmental friendliness, the sediment-modified planting eco-concrete with both H. verticillata and T. orientalis (SEC-H&T) was prepared and explored for the first time to achieve sustainable riparian restoration. Concrete mechanical characterizations showed that the compressive strength and porosity of SEC with 30% sediment content could reach up to 15.8 MPa and 21.25%, respectively. The mechanical properties and the sediment utilization levels of SEC were appropriately balanced, and potentially toxic element leaching results verified the environmental safety of eco-concrete modified with dredged sediments. Plant physiological parameters of both aquatic plants (biomass, chlorophyll, protein and starch) were observed to reach the normal levels in SEC during the 30-day culture period, and T. orientalis seemed better adapted to SEC environment than H. verticillate. Importantly, compared to SEC-H and SEC-T, SEC-H&T could effectively reduce the concentrations of COD, TN and TP by 58.59%, 74.00% and 79.98% in water, respectively. Notably, water purification mechanisms by SEC-H&T were further elucidated from the perspective of microbial community responses. Shannon index of bacterial diversity and proliferation of specific populations dominating nutrient transformation (such as Bacillus and Nitrospira) was increased under the synergy of SEC and aquatic plants. Correspondingly, functional genes involved in nitrogen and phosphorus transformation (such as nosZ and phoU) were also enriched. Our study can not only showcase an effective and flexible approach to recycle dredged sediments into eco-concrete with low environment impacts, but also provide a promising alternative for sustainable riparian restoration.

Developing Paraphalaenopsis labukensis (Shim, A. Lamb & C.L. Chan), an Orchid Endemic to Sabah, Borneo, Asymbiotic Seed Germination and In Vitro Seedling Development

Paraphalaenopsis labukensis Shim, A. Lamb & C.L. Chan (P. labukensis) is an endangered monopodial epiphytic orchid threatened due to habitat fragmentation and overharvesting. Consequently, this research aimed to achieve in vitro propagation of P. labukensis through asymbiotic seed germination and seedling development. This study focused on identification and optimizing capsule maturity, basal media and nutrient requirements. In addition, after hand pollinating the plant, their capsules’ flowers, length, girth, and colour variations were recorded weekly to ascertain morphological maturity characters of this species. Murashige and Skoog (MS), Knudson C (KC), and Vaccin and Went (VW) basal media were used to determine seed vegetation at 60, 90, and 120 days. Subsequently, for the proliferation and development of protocorms, the best basal media were those supplemented with different organic additives (coconut water (CW) and banana homogenate (BH)) and plant growth regulators (PGRs). As a result, 120 days after pollination (DAP) was chosen as the best capsule age for germination since the capsules had reached maturity. The highest germination rate was attained after 90 days of culture in Knudson C (KC) medium, with 98.78 ± 0.89%, followed by Murashige and Skoog (MS) medium, with 92.80 ± 3.26%. The KC supplemented with 0.5 mg/L NAA media documented a maximum percentage of 17.25 ± 0.96%. The 5 g/L (w/v) BH recorded a higher protocorm proliferation percentage than CW. Additionally, after 150 days of culture (DOC), this medium combination produced the most leaves, averaging four or five. The result of this present study has successfully established an effective in vitro propagation protocol for this species.

Conversion to Disposable Cystoscopes Decreased Post-procedure Encounters and Infections Compared to Reusable Cystoscopes.

We evaluated for differences in post-procedure 30-day encounters or infections following office cystoscopy using disposable vs reusable cystoscopes. Cystoscopies performed from June to September 2020 and from February to May 2021 in our outpatient practice were retrospectively reviewed. The 2020 cystoscopies were performed with reusable cystoscopes, and the 2021 cystoscopies were performed with disposable cystoscopes. The primary outcome was the number of post-procedural 30-day encounters defined as phone calls, patient portal messages, emergency department visits, hospitalizations, or clinic appointments related to post-procedural complications such as dysuria, hematuria, or fever. Culture-proven urinary tract infection within 30 days of cystoscopy was evaluated as a secondary outcome. We identified 1,000 cystoscopies, including 494 with disposable cystoscopes and 506 with reusable cystoscopes. Demographics were similar between groups. The most common indication for cystoscopy in both groups was suspicion of bladder cancer (disposable: 153 [30.2%] and reusable: 143 [28.9%]). Reusable cystoscopes were associated with a higher number of 30-day encounters (35 [7.1%] vs 11 [2.2%], P < .001), urine cultures (73 [14.8%] vs 3 [0.6%], P = .005), and hospitalizations attributable to cystoscopy (1 [0.2%] vs 0 [0%], P < .001) than the disposable scope group. Positive urine cultures were also significantly more likely after cystoscopy with a reusable cystoscope (17 [3.4%] vs 1 [0.2%], P < .001). Disposable cystoscopes were associated with a lower number of post-procedure encounters and positive urine cultures compared to reusable cystoscopes.

Brown sugar addition enhanced nutrient removal rates, growth performance, and bacterial community in a rice straw-based biofloc shrimp culture system

A 30-day culture trial was executed to ascertain the effects of brown sugar addition on nutrient removal, feed conversion ratio, growth performance, and microbial community in a rice straw-based biofloc shrimp system. Twelve indoor experimental barrels were supplied with juvenile pacific white shrimp (Litopenaeus vannamei) with a preliminary mean weight of ∼1.08 ± 0.35 g. The experimental groups comprised four biofloc treatments labeled as (Control-CT, SG1, SG2, and SG3), each with three replicates. The SG groups were the treatments with varying amounts of carbon source (brown sugar) addition. Each experimental barrel was stocked with 100 juvenile shrimps. To maintain the carbon: nitrogen ratio, brown sugar was added daily in varying amounts in the SG treatments but not in the control group (CT). The results demonstrated that the ammonium and nitrite‑nitrogen concentrations in the SG3 (0.45 and 0.34 mg/L) and SG2 (0.58 and 0.43 mg/L) groups were significantly (p < 0.05) lower than the Control (1.18 and 0.88 mg/L). Also, the highest nutrient removal rates for ammonium nitrogen (80%) and nitrite nitrogen (83.79%) were observed in the SG3 treatment. In addition, the SG2 group's feed conversion ratio (0.66) was statistically (p < 0.05) lower than the CT group's (0.83). Compared to the control setup (86%), the SG treatments recorded shrimp survival rates of over 90%. Furthermore, our results revealed that the most dominant microbial phyla in all treatments were Proteobacteria (71.60%), Bacteroidetes (26.60%), Actinobacteria (18.53%), Planctomycetes (8.30%), and Verrucomicrobia (2.40%) which played a significant role in nutrient cycling and promoting water quality. Overall, our study highlighted an innovative ecological farming system that recycles agricultural waste, minimizes inorganic nitrogen levels, and serves as an in-situ food source for sustainable shrimp production.

Utilization of microalgae, Chlorella sp. UMT LF2 for bioremediation of Litopenaeus vannamei culture system and harvesting using bio-flocculant, Aspergillus niger

Microalgae are well known as autotrophic microorganisms in aquaculture wastewater treatment, however their role in the aquaculture system is rarely explored. The purpose of this study is to evaluate the influence of adding microalgae, Chlorella sp. UMT LF2, on the functionality for bioremediation and growth performance of Whiteleg shrimp, Litopenaeus vannamei in the nursery phase reared in a control culture system. Secondly, the response surface methodology (RSM) was used to investigate further on the optimal condition for the harvesting process of excess microalgae biomass using bio-flocculant from the filamentous fungus, Aspergillus niger. The experimental set-up with Chlorella sp. additions were compared to the control group without the microalgae addition based on the water quality, microalgae biomass and shrimp growth performance. Water samples were collected and underwent in-situ and ex-situ involving nine physicochemical parameters. The results showed that introducing microalgae with zero water exchange as treatment tanks reduced the NH3, NO2− and PO43− during the intermediate until the two days before the 30-day culture period's end. Microalgae also enhanced shrimp survival and growth performance significantly 89% as compared to the control, 68%. Furthermore, the culture with the addition of microalgae maintained pH stability and enhanced dissolved oxygen during daytime in the culture water. Therefore, this finding confirmed that Chlorella sp. UMT LF2 addition is promising in improving rearing environment and nursery performance for L. vannamei in culture system. However, further research is required to demonstrate the harvesting by-product from the culture system and the potential applications.

Vibrio load and percentage composition of sucrose‐fermenting vibrios in Nile tilapia ( Oreochromis niloticus ) cultured in brackish water earthen ponds and biocontrol potential of recycled tilapia‐conditioned greenwater against population growth of V. parahaemolyticus and non‐sucrose‐fermenting vibrios in the grow‐out culture of white leg shrimp ( Litopenaeus vannamei )

Vibrio are known opportunistic pathogens of pond-cultured fish and shrimp. This study determined the presumptive Vibrio count (PVC) and percentage composition of “beneficial” sucrose-fermenting vibrios (SFVs) and “pathogenic” non-SFVs in the water, sediment, gills and intestines of healthy tilapia Oreochromis niloticus collected every 2 weeks from Days 30 to 120 post-stocking in brackish water earthen ponds. PVCs in water and sediment ranged from 102–104 CFU/ml/CFU/g while in tilapias' gills and intestines, PVCs ranged from 103–106 CFU/g and 102–106 CFU/g, respectively, with SFVs dominating in water, sediment, gills (≥50%), and intestines (≥80%) of tilapia. Because use of tilapia-conditioned green water (TCGW) for shrimp's grow-out culture has been reported effective against acute hepatopancreatic necrosis disease outbreaks caused by V. parahaemolyticus, PVC, SFVs/non-SFVs (%), and V. parahaemolyticus count (VPC) in the recycled TCGW and Litopenaeus vannamei's hepatopancreas were also examined from stocking until 105 days of culture (DOC) in earthen ponds. PVCs ranging from 102–103 CFU/ml and 103–104 CFU/g were noted in water and shrimp's hepatopancreas, respectively. While non-SFVs population in water varied, a downward trend typified by an abrupt 50% reduction was noted in hepatopancreas at DOC 42, and remained or further dropped until DOC 105. VPCs in water likewise varied (undetectable–102 CFU/ml) while in hepatopancreas, counts dropped to undetectable level from DOC 70 onwards. Current data illustrate that remarkable shift of SFVs' dominance in the water and concomitantly in shrimp's hepatopancreas, plays a pivotal role in regulating non-SFVs proliferation in shrimp's hepatopancreas via competitive exclusion.

Bioconversion of food waste to crayfish feed using solid-state fermentation with yeast.

In order to realize the value-added utilization of food waste (FW), the preparation of crayfish (Procambarus clarkii) feed by yeast fermentation was investigated. Firstly, the suitable fermentation condition was obtained through a single factor experiment as follows: the initial moisture of the FW was adjusted to 60% with bran and inoculated with a 2% yeast mixture (Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica, 3:2:1) followed by aerobic solid-state fermentation for 7days. The crude protein and acid-soluble protein contents in the fermented feed were 25.14% and 5.16%, which were increased by 8% and 140.67%, respectively. The crude fat content was 0.74%, decreased by 68.29%. The content of antioxidant glutathione (571.78μg/g) increased 63.33%, and the activities of protease and amylase increased nearly 9 and 3 times, respectively. The maximum degradation rates of aflatoxin B1, zearalenone, and deoxynivalenol were 63.83%, 77.52%, and 80.16%, respectively. The fermented feeds were evaluated by substituting (0%, 10%, 30%, 50%, and 100%) commercial diet for crayfish (30-day culture period). When the replacement proportion was 30%, the weight gain of crayfish reached 44.87% (initial body weight 13.98 ± 0.41g), which was significantly increased by 10.25% compared with the control (p = 0.0005). In addition, the lysozyme and SOD enzyme activities in crayfish hepatopancreas were also increased significantly. Our findings suggest that yeast-fermented feed from FW can replace 30% of crayfish's conventional diet, which may improve crayfish's antioxidant capacity and enhance non-specific immunity by providing molecules such as glutathione.

The dominance and proportions of plankton in Pacific white shrimp (Litopenaeus vannamei) ponds cultivated with the intensive system in Bulukumba Regency, South Sulawesi, Indonesia

This study aimed to evaluate plankton in Pacific white shrimp (Litopenaeus vannamei) cultivation in Bulukumba Regency, South Sulawesi. The study was conducted in six intensive ponds for 84 days from November 2019 to February 2020. Plankton samples were collected every 10 days for 8 weeks based on the day of culture (DOC) of Pacific white shrimp since the first rearing in the pond using plankton net (mesh size of 25 μm). Then, planktons were preserved to 5% formalin buffer in 250 mL of sterile plastic. Next, the plankton densities and compositions were analyzed quantitatively and qualitatively. The results showed that plankton dominance in Chlorophyta species and the presence was evenly distributed across all shrimp ponds in the field. The number was relatively stable in all shrimp DOCs and was the highest proportion as well; Chlorophyta (73 to 83%), Diatom group (7.75 to 15.63%), and blue-green algae (BGA) group (7.13 to 13.50%). Plankton can be used as a biomonitor of pollution and shrimp health in dominance and the percentage proportion of each species. Regular monitoring is highly recommended to minimize plankton growth, especially the BGA type that can harm shrimp health in the intensive system.

In vitro direct organogenesis of the Cretan dittany (Origanum dictamnus L.), an important threatened Greek endemic species

Dittany of Crete (Origanum dictamnus L.) is a threatened medicinal-aromatic plant of Lamiaceae family which is a local endemic to the Island of Crete, Greece. Its high culinary use and increasing demand in the pharma, perfumery, cosmetic and food industry along with its overexploitation from its natural habitat has threatened this species and has necessitated its large-scale production for industrial exploitations using advanced technologies. Micropropagation is considered a good tool for ex situ conservation of endangered species with reduced populations in the wild, low germination rates and low seed production. In this study, moderate germination percentages (40-41.38%) were exhibited for seeds after 40 days of culture at 21-23 oC in MS medium regardless of photoperiod regime (16h light/ 8h dark, 24h darkness), without significance difference. In the proliferation and rooting stage, three basal culture media (MS, WPM, Gamborg B5) were tested in combination with two concentrations of 6-benzyladenine (BA) (1.1, 2.2 μM) and indole-3-butyric acid (IBA) (0.125, 0.25 μM), all supplemented with 0.3 μM gibberellic acid (GA3), 20 g L-1 sucrose and 6 g L-1 Plant Agar (pH: 5.8). The results showed that the MS medium + 2.2 μM BA + 0.25 μM IBA was the most effective treatment for micropropagation of shoot nodal explants in a single stage within a 30-day culture period, exhibiting 85% shoot formation, 1.8 new shoots/ explant 2.8 cm long with a 3.2 proliferation rate, 100% rooting, 16.5 roots/ rooted explant 2.1 cm long. Rooted plants obtained in vitro from MS medium enriched with 2.2 μM BA + 0.25 μM IBA gave 100% ex vitro survival rate on a peat: perlite (1:1 v/v) substrate mixture after 2 months in the greenhouse mist. In this study, an efficient in vitro propagation system of O. dictamnus is described for the first time through optimization of direct organogenesis stages (seed germination, proliferation, rooting, ex vitro acclimatization), as a means to facilitate domestication procedure, ex-situ conservation and future sustainable exploitation strategies, thus promoting wider usability of this local endemic with significant commercial potential.

Accumulation potential of heavy metals at different growth stages of Pacific white leg shrimp, Penaeus vannamei farmed along the Southeast coast of Peninsular India: A report on ecotoxicology and human health risk assessment

This study compared the heavy metal concentration in water, sediment, and shrimp at different growth stages of culture and subsequently evaluated the ecotoxicological and human health risk status. Total trace element concentration in the water, sediment and shrimp ranged from not detected (ND) (Hg) to 91.05 (Fe) μg/L, 0.01 (Hg) to 19, 246.33 (Fe) mg/kg, and ND (Hg) to 13.98 (Fe) mg/kg, respectively. Toxic metals such as, Cd, Hg, and Pb in shrimps ranged from ND to 2.11 mg/kg, ND to 0.158 mg/kg, ND to 0.088 mg/kg, and ND to 0.469 mg/kg, respectively. Toxic heavy metals at all the growth stages of shrimps (days of culture (DOC)-01 to DOC-90) were found below the maximum residual limit (MRL) of 0.5 mg/kg set by the European Commission (EC). Similarly, Cu, Zn, and As concentrations in shrimp were also far below the MRLs of 30 mg/kg, 100 mg/kg, and 76 mg/kg set by the World Health Organization and Food Safety and Standard Authority of India, respectively. The concentration of heavy metals increased from DOC-01 to DOC-90 and was positively correlated with the length and weight of the shrimps (p < 0.05). The risk assessment was estimated for both Indians and Americans and found no carcinogenic (lifetime cancer risk (LCR) < 10−4) and non-carcinogenic (THQ and TTHQ<1) health risks through consumption of shrimp cultured in this region. The hazard quotient (HQdermal < 1), hazard index (HI < 1), and LCR (<10−4) values of the heavy metals indicated that the dermal absorption might not be a concern for the local fishermen and marine fish/shrimp farmworkers. Water and sediment quality indices were applied to assess the surface water and sediment quality, and their results were found nil to low levels of heavy metal contamination at all the sampling sites. All heavy metals studied in sediments were < effect range low (ERL) and < threshold effect level (TEL), indicating no adverse biological effects on aquatic organisms. Therefore, regular monitoring of the shrimp aquaculture system throughout the crop will provide evidence of heavy metals bioaccumulation in shrimps. This research will provide baseline data to help farmers establish the optimal aquaculture practices and regulatory authorities to formulate legislation and strategies to reduce heavy metal biomagnification in shrimps from farm to fork.

A C∧S-Cyclometallated Gold(III) Complex as a Novel Antibacterial Candidate Against Drug-Resistant Bacteria.

The worldwide emergence and spread of infections caused by multidrug-resistant bacteria endangers the efficacy of current antibiotics in the clinical setting. The lack of new antibiotics in the pipeline points to the need of developing new strategies. Recently, gold-based drugs are being repurposed for antibacterial applications. Among them, gold(III) complexes have received increasing attention as metal-based anticancer agents. However, reports on their antibacterial activity are scarce due to stability issues. The present work demonstrates the antibacterial activity of the gold(III) complex 2 stabilized as C∧S-cycloaurated containing a diphenylphosphinothioic amide moiety, showing minimum inhibitory concentration (MIC) values that ranged from 4 to 8 and from 16 to 32 mg/L among Gram-positive and Gram-negative multidrug-resistant (MDR) pathogens, respectively. Complex 2 has a biofilm inhibitory activity of only two to four times than its MIC. We also describe for the first time a potent antibacterial synergistic effect of a gold(III) complex combined with colistin, showing a bactericidal effect in less than 2 h; confirming the role of the outer membrane as a permeability barrier. Complex 2 shows a low rate of internalization in Staphylococcus aureus and Acinetobacter baumannii; it does not interact with replication enzymes or efflux pumps, causes ultrastructural damages in both membrane and cytoplasmic levels, and permeabilizes the bacterial membrane. Unlike control antibiotics, complex 2 did not generate resistant mutants in 30-day sequential cultures. We detected lower cytotoxicity in a non-tumoral THLE-2 cell line (IC50 = 25.5 μM) and no acute toxicity signs in vivo after an i.v. 1-mg/kg dose. The characterization presented here reassures the potential of complex 2 as a new chemical class of antimicrobial agents.

Melatonin-Medicated Neural JNK3 Up-Regulation Promotes Ameloblastic Mineralization.

Introduction: Melatonin, an endogenous neurohormone, modulates the biological circadian rhythms of vertebrates. It functions have been reported in previous stomatological studies as anti-inflammation, antioxidant, osseointegration of dental implants and stimulation to dental pulp stem cells differentiation, but its role in ameloblastic differentiation and mineralization has been rarely studied. Objective: To reveal the effects of melatonin on the mineralization of ameloblast lineage cells (ALCs), and to identify the change in gene expression and the potential mechanism based on ribonucleic acid sequencing (RNA-seq) analysis. Method: ALCs were induced in melatonin-conditioned medium. After 7-days culture, Western blot, real-time PCR, alkaline phosphatase (ALP) activity test, RNA-seq were accordingly used to detect the change in molecular level. After 1-month odontogenic induction in melatonin medium, Alizarin Red-S (ARS) staining showed the changes of mineral nodules. Differentially expressed genes (DEGs), enrichment of functions and signaling pathways analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) database were performed. The JNK3 antagonist (JNK3 inhibitor IX, SR3576) and β-arrestin1 (Arrb1) overexpression were applied to confirm the fluctuation of melatonin-medicated JNK3 and Arrb1 expression. Results: In this study, we found out melatonin contributed to the ameloblastic mineralization, from which we can observed the elevated expression of enamel matrix protein, and increased ALP activity and mineralized nodules formation. RNA-seq analysis showed the up-regulation of neural JNK3 and down-regulation of Arrb1 in ALCs. Meanwhile, phosphorylated JNK3 deficiency (phosphorylated JNK3 inhibitor---SR3576 added to culture medium) led to mineralization delay, and Arrb1 overexpression proved Arrb1 takes bridge between melatonin receptors (MTNR) and JNK3 in MAPK signaling pathway.

Growth performance, production and economic viability of Indian white shrimp (Penaeus indicusH. Milne Edwards) fed with varying dietary protein levels

The growth efficiency, productivity and economic viability of Indian white shrimp (Penaeus indicus) fed with diet containing 40% (CPhigh) and 34% (CPlow) crude protein (CP) levels were determined in a 90-day grow-out culture trial. Growth parameters including average body weight (ABW), specific growth rate (SGR), survival and feed conversion ratio (FCR) were not statistically different. CPlow had lower overall shrimp production (797.53 kg/ha, DOC 90), but was not significantly different from CPhigh (843.78 kg/ha, DOC 90). The mean values for the water parameters of both treatments, such as DO, pH, salinity, temperature, TAN, NO2-N, NO3-N and PO4-P, also showed no significant differences. However, the TAN values of CPhigh were consistently higher from day of culture (DOC) 63 and increased significantly (p = .048) at DOC 90. Furthermore, the total bacterial and Vibrio counts in both treatments were not significant throughout the culture period. The economic analysis revealed that CPlow obtained higher net profits (6093 USD/ha/year), return on investment (72%) and discounted benefit–cost ratio (1.73). The current study found that feeding a low protein diet to P. indicus is economically viable and profitable and results in improved growth efficiency and productivity while also improving water quality and lowering nitrogen discharge.

Influence of environmental variables on methane related microbial activities in a tropical bio-secured zero-exchange shrimp culture system

Recently, aquaculture has emerged as the fastest growing food-producing sector accounting for nearly 50% of the world's food fish and is an activity of economic importance worldwide. Aquaculture systems are considered as one of the potential contributors to atmospheric methane (CH4)—the second most important greenhouse gas (GHG). The present study was undertaken to assess the influence of environmental variables on the abundance of culturable methanotrophs (MOB), methane oxidation activity (MOA) and methane production activity (MPA) during a grow-out cycle in zero-exchange shrimp pond growing whiteleg shrimp, Litopenaeus vannamei. During the 96 days of culture (DoC), the abundance of MOB in the pond water and sediment, ranged between 3.04 × 103–1.8 × 104 CFU mL-1 and 3.36 × 105–3.17 × 106 CFU g-1, respectively. The mean potential rates of MOA and MPA in pond sediments were 392.71 ± 53.06 µmole g-1d-1 and 0.60 ± 0.30 µmole g-1d-1, respectively. The abundance of MOB and methane related activities were strongly influenced by the dissolved nitrogen species and total organic carbon (p < 0.05). In addition to providing the baseline data on microbial mediated methane activities, the study highlights the importance of methane oxidation/production processes in commercial earthen shrimp aquaculture system and the influence of environmental variables in regulating these processes. The results of this study would aid in developing environmental friendly management processes to reduce the efflux of GHG methane from shrimp aquaculture systems which is a thriving industry in the food sector.

Expression Virus-Like Particles (VLPs) at Geomembrane and Concret in Asian Pacific Shrimp Culture (Litopenaeus vannamei)

Asian Pacific Shrimp is an invertebrate that the most culture in aquaculture. But the high demand for shrimp makes farmers cultivate a high density. There are several ways to increase the density of shrimp culture, usually called geomembrane plastic and concrete ponds. The ponds are located in the Laboratory of Brackishwater and Seawater Fisheries, Probolinggo and Lucky Windu, Situbondo. Day of Culture (DOC) on Laboratory of Brackishwater and Seawater Fisheries in Probolinggo pond is 85 days both, while in Lucky Windu Situbondo is 81 days on pond 2, and pond 3B 133 days. The study aimed to evaluate correlations of VLPs towards geomembrane and concrete ponds. The research method has two observations: 1. Periodic observations; nitrite, ammonium, and shrimp were observed; 2. Last observation; sampling water for analysis VLPs was observed. Data of sampling water in the different ponds were then analyzed using Pearson correlation analysis to look for the level of tightness and direction of the relationship. The results have obtained that geomembrane VLPs and concrete VLPs has a very strong relationship, while the type of geomembrane and concrete was close to 1 &gt; 0.5 and the result is 0.90, 0.96, 0.69, and 0.82. Water quality showed pH 8.1 at geomembrane, nitrite 0.2mg.L-1 at geomembrane, and ammonium of 0.44 mg.L-1 at concrete. The pond area in geomembrane pond 1 and 2 was 1600 m2, meanwhile in concrete both is 4300 m2, which mean in concrete ponds more the existence of VLPs is because due to the different pond area factors and indicates from detections of WSSV that the result was positive that makes environment factor in abundances VLPs. But VLPs have no effect on the growth of shrimp vaname during the cultivated process.Keywords: Asian Shrimp Pasific (L. vannamei), Virus-Like Particles (VLPs), Water Quality, and WSSV.

The application of progressive systems in high density vannamei shrimp culture

The increase of super-intensive pond waste and the rearing period of high-density shrimps, has been reported to be a problem of environmental quality deterioration, which is accompanied by the chance of disease outbreak. Therefore, a progressive system with two phases of cultural activities, namely nursery and grow-out, is known to be an alternative in the process of avoiding the critical period between Day of Culture (DOC) 30-50, as well as increasing the chances of a successful culture. This research aims to examine the application of a progressive system, in the super-intensive culture of vannamei shrimps. The two methods used were Progressive & Non-Progressive treatments (PG & NPG). The NPG was used by directly stocking PL-10 to a grow-out pond of 1,000 m2, with a density of 500 PL/m2. However, PG (nursed for 21 days) was used by stocking PL-10 to PL-31 in 100 m2 pond with a density of 5,000 PL/m2, which were then transferred to a grow-out pond of 1,000 m2. The results showed that the PG treatment had better water quality parameters compared to the NPG. The survival rate, production, and feed conversion ratio in the PG treatment produced better performance than the NPG, with differences in the value of feeds used and yield of shrimp sales at 25.64% and 64.33%, respectively.