Commercial Culture Research Articles

Comparison of intra-assay and inter-assay reproducibility and positive detection times of two different (BacT/Alert 3D and Autobio BC) commercial blood culture systems.

In our study, we aimed to compare the performance of the BacT/Alert 3D (bioMerieux, France) system, which is currently used in our laboratory, and the Autobio BC (Autobio, China) system, which was newly introduced in our country, using standard and clinical isolates. Bacterial suspension was prepared by two technicians on the same day and three consecutive days from five different standard strains with 0.5 McFarland turbidity, then serial dilution to a final concentration was adjusted and was simultaneously inoculated in aerobic blood culture bottles. The bacterial concentration was measured by making a quantitative counting plate. The same procedure was also performed for 55 clinical isolates belonging to eleven species. After simulated bacteremia with standard and clinical isolates, the growth results were confirmed by inoculation from positive blood culture bottles onto solid medium and identification was made in the next day with MALDI-TOF MS (bioMérieux). In each study, sterile saline and blood was inoculated into the bottles as a negative control to check contamination. Intra-assay and inter-assay reproducibility of recovery rates and detection times of standard strains; recovery rates and detection times of clinical isolates were compared for both systems. Recovery rates were 100% in both systems, and when positive detection times were compared, it was found that there was no difference between the two devices in clinical isolates (p:0.262) but that Autobio BC gave significantly (p<0.001) earlier results in standard strains. In our simulated bloodstream infection study, Autobio BC was found to be comparable with BacT/Alert 3D, both recovery rates and growth detection time performance were found to be very good, and it can be used in routine microbiology laboratories.

Innovation agglomeration and heterogeneity: a micro-geographic measure

ABSTRACT This study develops two novel agglomeration indexes, combining the feature unbalance agglomeration index family and the distance-based agglomeration index family, to measure innovation agglomeration. We examine the positive effects of innovation agglomeration on the industrial total factor productivity (TFP). We discuss the factors driving the innovation agglomeration at the city level and analyze them in cities of the Yangtze River Delta (YRD). We find proximity to central cities and nearest ports has a positive impact, industrial level has an inverse U-shape impact, investment and commercial culture have positive impacts, and innovation policy has a negative impact. We identify five innovation agglomeration factors and discuss their effects on the theoretical and practical R&D management applications and strategies.

Identification of Albopleistophora grylli n. gen. n. sp. (Microsporidia) and its impact on crickets (Gryllus spp.) in food-and-feed culture systems

This study provides a comprehensive taxonomic description of a microsporidian parasite infecting crickets, Gryllus bimaculatus and G. assimilis. Our analysis includes gross pathology, histopathology, spore ultrastructure, parasite development cycle, single gene phylogenies, and phylogenomic comparisons. We introduce a new taxon, Albopleistophora grylli n. gen. n. sp., characterised by its unique developmental stages within a sporophorous vesicle, leading to the formation of mature spores measuring 5.7 × 2.8 µm. Although prevalent in commercial cricket cultures, this parasite seemed to have limited effects on cricket survival. Indeed, microsporidia exposure and density assays with the host G. bimaculatus, only revealed density as a significant factor affecting the crickets’ survival. Nevertheless, exposure showed significant effect on the crickets’ emergence time, where exposed crickets emerged as adults earlier than unexposed individuals. Moreover, exposure to the parasite increased the faeces production and weight gain in cricket males. However, neither exposure nor density significantly impacted the females’ fecundity. The absence of spores in non-exposed cricket groups suggested a horizontal transmission, highlighting the importance of controlled rearing practices to eliminate this microsporidium in control groups. The well-known anti-microsporidian drug ‘fumagillin’ was studied with a higher microsporidia dose of exposure to evaluate any improvement in cricket survival, without showing any significant differences between exposed and unexposed groups. Our findings underscore the nuanced dynamics of host-microsporidia interactions and emphasise the need for ecological context in understanding microsporidian impacts. Even if non-dangerous for its host, monitoring of this parasite seems crucial due to its potential zoonotic transmission by its close phylogenomic relation to human-infecting microsporidia species.

Molecular Identification, Histopathology and Antibiotic Susceptibility Profiling of Aeromonas veronii Isolated from Oreochromis niloticus in Bangladesh.

Tilapia (Oreochromis niloticus) is the most widely cultured freshwater fish species in Bangladesh and worldwide. However, commercial tilapia culture systems face increasing challenges from bacterial infections. The objective of this study was to identify the bacterial isolates from infected tilapia inan intensive cage culture farm located along the Shitalakshya River in Bangladesh. Infected fish samples were collected and underwentcomprehensive clinical and post-mortem investigations, followed by phenotypic, biochemical and molecular identification of the bacterial isolates, as well as histopathological and antibiotic susceptibility examinations. Phenotypic and biochemical characterization showed similarities of the -collected isolates with Aeromonas veronii. Moreover, molecular analysis of the bacterial conserved region 16S rRNA also confirmed these isolates as A. veronii. The analysed 16S rRNA sequence (GenBank accession no. PP832815) showed a close relationship (100% identity) with A. veronii from China (GenBank accession no. MT071624) in the NCBI BLAST search, and in the phylogenetic tree, they grouped in a single clade. This close genetic relationship is also supported by the low genetic distance between the isolates. Histopathological analysis revealed gross pathological changes like necrosis, hypertrophy and inflammation in muscle tissues. The isolates were found to be sensitive to multiple antibiotics but resistant to trimethoprim and sulphamethoxazole. This study investigated the presence of A. veronii infection in tilapia (O. niloticus) in an intensive cage culture farm in Bangladesh.

Culture Expansion Alters Human Bone Marrow Derived Mesenchymal Stem Cell Production of Osteoarthritis-relevant Cytokines and Growth Factors

PurposeThe purposes of this study were to characterize the human bone marrow derived mesenchymal stem cells (BM-MSCs) production of osteoarthritis-relevant cytokines and growth factors as they are purified and multiplied, a process termed culture expansion, and to compare the immunomodulatory potential of BM-MSCs based on source and medium used for culture expansion. MethodsBM-MSCs were obtained from iliac crest bone marrow aspirates of four healthy donors. These four BM-MSC cell lines underwent four rounds, or “passages,” of the institutional culture expansion protocol, using institutional culture media. The secretory molecules known to play a role in OA-related inflammatory immune response, cartilage degradation and patient symptoms, together called the BM-MSC “secretome,” were measured at each passage. Three lines of commercially available BM-MSCs from healthy donors underwent culture expansion by the same protocol, using commercial culture media. The commercial BM-MSCs secretome and the institutional BM-MSCs secretome were compared at each passage. Significance was set at p<0.05. ResultsInstitutional BM-MSCs produced less IL-6 at passages 3 (237±113 pg/mL) and 4 (237±113 pg/mL) compared to passages 1 (884±97 pg/mL) and 2 (1071±129 pg/mL; p<0.01). Institutional BM-MSCs produced more MIP-3α at passage 4 than at passage 1 (106±41 vs 32±7 pg/mL; p<0.01). Across passages of culture expansion, institutional BM-MSCs grown on institutional medium expressed more IL-6 (P<0.001), IL-10 (P<0.001), IL-1β (P<0.001), TNFα (P=0.004), and VEGF-C (P=0.003) than commercially available BM-MSCs grown on commercial medium. ConclusionCulture expansion alters key molecules within the BM-MSC secretome. Additionally, differences in BM-MSC source and culture medium alter the BM-MSC secretome and its immunomodulatory potential.

Lactobacilli as additional cultures in cheese making

Production of cheeses from thermally processed milk at an industrial scale is impossible without using commercial bacterial starter cultures that include a limited number of species and strains of microorganisms. This leads to the fact that sensory indicators of mass-produced cheeses practically do not differ. Traditional cheeses from unpasteurized milk are distinguished by more pronounced and diverse tastes. Scientific literature describes the significant taxonomic variety of microbiota of traditional cheeses, including non-starter lactobacilli. Sensory indicators and safety of cheeses directly depend on the composition of this microbiota. This study examines the main moments of the taxonomic reform of lactobacilli, which resulted in union of two families Lactobacillaceae and Leuconostocaceae, and division of the genus Lactobacillus into 25 genera. New description of the family and several species of lactobacilli used in starter cultures is given. The authors demonstrate the complex autochthonous microbiota of cheeses and a possibility of stabilization of fermentation upon cheese making from raw milk and improvement of their quality without losing individuality due to the introduction of selected autochthonous additional cultures. When cheeses are made from pasteurized milk, these cultures improve sensory characteristics of a product and impart the original flavor to them. Several studies show that probiotic bacteria intensively develop and maintain viability for a long time even in long-ripened cheeses. Such cheeses can be carriers of live probiotics and their metabolites that are beneficial for the consumer health. This review summarizes information about promising directions of extension of the species spectrum of additional cultures for creation of domestic starter cultures for cheese making. Taking into consideration that microbiology of cheese making is quite a wide field that is not fully studied, the review does not claim to be the comprehensive analysis of all existing approaches.

Reusable Immobilized Lactobacillus futsaii CS3 for Enhanced GABA Synthesis using Low-Cost Substrates in Fermenter-Scale Batch and Fed-Batch Fermentations

On the industrial scale, the cost of commercial culture media for the production of gamma-aminobutyric acid (GABA) is a very important factor. This study employed a low-cost substrates and by-product from agri-food industry for GABA synthesis by Lact. futsaii CS3 at the fermenter-scale. Lact. futsaii CS3 cells were immobilized in 3 % (w/v) sodium alginate and employed for GABA synthesis in the optimal modified MRS medium (3.48 % (w/v) cane sugar, 3.84 % (w/v) tuna condensate waste and 10.77 % (w/v) monosodium glutamate (MSG)) with the initial pH medium of 5, fermentation temperature at 37 °C and agitation speed at 30 rpm. During the 60th h of batch fermentation without pH control, immobilized Lact. futsaii CS3 efficiently transformed MSG into the highest GABA of 19.05 g/L, achieving the volumetric productivity of 0.32 g/L/h with a bioconversion rate of 29.01 %. To further enhance GABA production, MSG (7.5 % w/v) was fed into the fermenter during the 48th h of fed-batch fermentation, aiming to amplify GABA synthesis. The maximum GABA (26.28 g/L) was synthesized at 84 h of fed-batch fermentation, and the volumetric productivity and a bioconversion rate of 0.31 g/L/h and 23.59 %, respectively, were obtained. Fed-batch fermentation significantly outperformed batch fermentation, resulting in a 37.95 % increase in GABA production. Moreover, immobilized Lact. futsaii CS3 cells could be reused in 2 batch cycles. In the 1st reusability, the maximum GABA synthesis reached 25.94 g/L, and the volumetric productivity and a bioconversion rate of 0.31 g/L/h and 23.29 %, respectively, were achieved at 84 h of fed-batch fermentation. While in the 2nd reusability, GABA synthesis decreased to 23.29 g/L, with the volumetric productivity and a bioconversion rate of 0.28 g/L/h and 20.91 %, respectively, at 84 h of fed-batch fermentation. HIGHLIGHTS GABA production utilizing agri-food industry by-product. GABA production was enhanced by cane sugar and tuna condensate waste. Immobilized futsaii CS3 produced GABA 19.05 g/L (batch). Immobilized futsaii CS3 produced GABA 26.28 g/L (fed-batch). Immobilized futsaii CS3 could be reused in 2 batch cycles on GABA production. GRAPHICAL ABSTRACT

THE IMPACT OF STARTER CULTURES ON QUARK TYPE CHEESE PRODUCTION

This study was conducted to investigate the effect of starter cultures on the physicochemical and microbiological properties, texture, yield, and consumer preferences of quark type cheese. For this purpose, three different quark cheeses were manufactured by using commercial starter cultures. The microbiological, physicochemical, textural, and sensory properties of the cheese samples were determined at 1st, 14th, and 28th days of the storage period. The results showed that the kind of starter culture used in production influences the composition and yield of the obtained quark cheeses. It has been determined that the use of kefir culture in quark cheese production influences the moisture and water holding capacity, and as a result, improves its spreadability. Also, the sensory analysis exhibited that cheese produced with kefir culture had higher texture and taste-flavor acceptability. The study indicates that kefir culture may be successfully used in quark cheese production.

Use of Indigenous Lactic Acid Bacteria for Industrial Fermented Sausage Production: Microbiological, Chemico-Physical and Sensory Features and Biogenic Amine Content

The use of starter cultures in the meat industry is common, even if the number of available commercial cultures is limited, inducing product standardisation and microbial diversity reduction. On the other hand, some artisanal products relying on spontaneous fermentation can represent a source of isolation of new interesting strains. In this work, four LAB strains derived from Mediterranean spontaneously fermented sausages were tested as new starter cultures for the industrial production of fermented sausages, in comparison to a commercial starter culture. The products obtained were analysed for physico-chemical parameters, microbiota, biogenic amines and aroma profile. A consumer test was also performed to evaluate product acceptability. The strains induced different acidification kinetics. LAB counts showed high persistence when Latilactobacillus curvatus HNS55 was used as the starter culture, while the addition of Companilactobacillus alimentarius CB22 resulted in a high concentration of enterococci (6 log CFU/g), 2 log higher than in other samples. Tyramine was detected at concentrations of 150–200 mg/kg, except for in the sample produced with Lactiplantibacillus plantarum BPF2 (60 mg/kg). Differences were observed in the aroma profile, with a high amount of 2-butanone found in the samples obtained with Comp. alimentarius CB22. These latter sausages also showed the lowest score in terms of acceptability. This study allowed us to select new LAB strains for fermented sausage starter cultures, increasing the product diversification.

Establishment and characterization of novel spontaneously immortalized larval cell lines from sablefish Anoplopoma fimbria.

Sablefish Anoplopoma fimbria is a groundfish of the North PacificOceantypically found in sea floor habitat at depths to 2700m. Prized as a food fish with exceptionally high market value, sablefish aquaculture has been sought to provide a sustainable source of this fish to meet market demands. While commercial culture has successfully produced market-sized fish in Pacific coastal environments, production has been hampered by disease and the overall lack of information on sablefish health and immunology. To begin to address these knowledge gaps, herein we describe the isolation and characterization of spontaneously immortalized sablefish larval cell lines (AFL). Six sublines were established from pools of early yolk-sac larvae, while attempts to develop tissue-specific-derived cell lines were unsuccessful. The six yolk-sac larval cell lines each display two morphologies in culture, an elongated fibroblast-like cell type, and a rounded squamous or epithelial-like cell type. Cytogenetic characterization suggests that both cell types are diploid (2n = 48) with 24 pairs of chromosomes, 23 pairs of autosomes, and 1 pair of sex chromosomes. A small proportion (11%) of AFL cells display tetraploidy. Incubation temperature and medium composition experiments revealed HEPES buffered L-15 media containing 10-20% FBS at temperatures between 15 and 18° C yielded optimal cell growth. These growth characteristics suggest that sablefish larval cells display a robustness for varying growth conditions. The establishment of AFL cell lines provides a foundational tool to study the physiology, health, immunology, and cell and molecular biology of sablefish.

Identification, Safety Assessment, and Antimicrobial Characteristics of Cocci Lactic Acid Bacteria Isolated from Traditional Egyptian Dairy Products.

The main objective of this study is to isolate and identify lactic acid bacteria (LAB) from various Egyptian dairy products, examine their antibacterial and hemolysis potential, and ensure their safety when used as starter cultures in different dairy industries. Egyptian dairy products are often made without the use of commercial starter cultures, using raw milk and artisanal methods. The most popular traditional dairy products are Laban Rayeb and Zabady, as well as the cheese varieties of Ras, Domiati, and Karish. The microbial communities used for fermentation and the diversity of lactic acid bacteria are the most important factors that can affect the quality of these products. In order to investigate the diversity of cocci lactic acid bacteria in Egyptian dairy products, 70 samples of raw or fermented milk and cheeses were collected from traditional cheese-making factories, local markets, and farmhouses located in the Delta area of Egypt. Following this, the LAB were isolated from the samples. One hundred fifty-seven isolates of Gram-positive, catalase-negative, and cocci bacterial species were identified via rep-PCR, and some isolates were confirmed using pheS and 16S rRNA gene sequencing, as follows: Streptococcus infantarius subsp. infantarius (three isolates), Enterococcus hirae (three isolates), Enterococcus faecium (ninety-six isolates), Enterococcus faecalis (forty isolates), Enterococcus durans (six isolates), Lactococcus garvieae (one isolate), Pediococcus acidilactici (seven isolates), and Lactococcus lactis subsp. Lactis (one isolate). These findings validate that five strains have strong antibacterial activity against Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes, and one hundred thirty-four strains were safe for hemolysis. The five strains were selected as protective cultures, including Pediococcus acidilactici, Lactococcus lactis subsp. lactis, E. faecalis, and E. faecium.

Una chacra en Montevideo, dos hoteles en Carnac. Tres casos paradigmáticos de ciencia en lugares impensados a ambos lados del Atlántico

This article focuses on two places that acted as spaces of training or “scientific” sociability for archaeology and palaeontology in the nineteenth century: two hotels in Brittany and a small house in Montevideo, which were meeting points and places for the exchange of ideas among the fieldworkers of these disciplines in the making. The spaces discussed here have in com- mon their being located in regions far from the main scholarly institutions: this is a phenomenon that occurs in the private sphere, at the crossroads of a literate and commercial culture that characterizes the scientific practices of Europe and Latin America, in spaces that are not necessarily linked to state or metropolitan infrastructures. The study of places that are removed from the metropolis reveals the great similarity between European and non-European provincial localities, which explains why Montevideo and Carnac are brought together in the same article.

Comparison and evaluation of neutralization of clinically frequently used antimicrobial agents using three different culture media in simulated blood cultures.

We present a study on performance comparison of three different commercial culture media for neutralization of antibiotic effects in simulated blood cultures. BACT/ALERT (FA Plus and FN Plus) culture media with novel resin showed absolute advantages over DL and REDOX culture media at %PSL concentration of antimicrobials.

The Socio-economic Transformation in Makassar Tribe Gift-giving Tradition: Reconstructing Social Welfare Strategy

The gift-giving tradition in Jeneponto, the land of the Makassar Tribe, has undergone significant transformation over time, reflecting changes in socio-economic ethics within societies. This study explores the evolution of this tradition and its profound impact on contemporary socio-economic values. It examines how gift-giving has transitioned from a simple act of goodwill and cultural exchange to a complex phenomenon influenced by consumerism, status, and economic disparities. Drawing from ethnographic research analysis, this research delves into the cultural and social significance of gift-giving in various contexts. It sheds light on how traditional values, such as reciprocity and generosity, have been reshaped by commercialization and global consumer culture. Furthermore, it investigates the consequences of these changes on individuals and communities. The study also discusses the ethical dilemmas arising from the commodification of gift-giving, including issues of authenticity, social inequality, and environmental sustainability. It highlights the need for a more conscious and responsible approach to gift-giving in the current situation.

Acidic polymers reversibly deactivate phages due to pH changes.

Bacteriophages are promising as therapeutics and biotechnological tools, but they also present a problem for routine and commercial bacterial cultures, where contamination must be avoided. Poly(carboxylic acids) have been reported to inhibit phages' ability to infect their bacterial hosts and hence offer an exciting route to discover additives to prevent infection. Their mechanism and limitations have not been explored. Here, we report the role of pH in inactivating phages to determine if the polymers are unique or simply acidic. It is shown that lower pH (=3) triggered by either acidic polymers or similar changes in pH using HCl lead to inhibition. There is no inhibitory activity at higher pHs (in growth media). This was shown across a panel of phages and different molecular weights of commercial and controlled-radical polymerization-derived poly(acrylic acid)s. It is shown that poly(acrylic acid) leads to reversible deactivation of phage, but when the pH is adjusted using HCl alone the phage is irreversibly deactivated. Further experiments using metal binders ruled out ion depletion as the mode of action. These results show that polymeric phage inhibitors may work by unique mechanisms of action and that pH alone cannot explain the observed effects whilst also placing constraints on the practical utility of poly(acrylic acid).

Influence of Modified Cassava Starches on the Rheological and Structural Properties of a Fermented Soy Beverage During Storage

AbstractTraditionally, intensive thermal treatments are applied to process soy beverages, negatively impacting product quality by reducing solubility, and viscosity, while promoting syneresis. Modified cassava starches can prevent these effects. This study evaluates the influence of adding modified cassava starches on syneresis, apparent viscosity, particle size, microstructure, and sensory acceptance of a fermented soy beverage. A commercial culture of starter microorganisms and probiotics is used in the fermentation. Four beverages are produced: one with native cassava starch, one with octenyl succinic anhydride (OSA)‐modified cassava starch, one with crosslinked acetylated distarch adipate (ADA), and one with crosslinked‐substituted cassava starch (mixed); the starch concentration is 1% in each beverage. Samples are stored for 3 weeks at 4 °C. Modified cassava starches significantly alters syneresis compared to the native starch beverage, with no difference among the other treatments. Viscosity shows significant differences among treatments. During storage, the native starch beverage shows an increase in syneresis and a reduction in viscosity, whereas the OSA‐modified starch beverage has higher viscosity but presents significant variation by the end of the 3‐week storage period. The mixed starch beverage has intermediate characteristics with high viscosity and stability during storage. In the sensory evaluation, the consumers prefer the OSA‐modified starch beverage.

Effect of Synthetic Hormone on Breeding Potential of Gold Fish (Carassius auratus)

The acquisition of ornamental fish is becoming a prerequisite for luxury. Fish which are ornamental are getting progressively more popular as a way to alleviate stress. Among these, goldfish and koi carp are the most prevalent visually appealing fish that happen to be consistently in demand by fish hobbyists. For millennia, the method of raising these fish has been standardized. One of the most significant advancements in the aquaculture of ornamental fish that are vital to economic prosperity is artificial propagation. Induced breeding is a straightforward approach that guarantees a timely supply of seed spawn for fish culture. The aim of the current study was to use ovaprim™ hormone at various dosages to encourage breeding in gold fish (Carassius auratus auratus) kept in captivity. Every breeding pair, including the control, was bred. There were significant (&lt;0.05) variations in the success of fertilization and hatching rate at various doses between treatments and the control group. Ovaprim™ at a dose of 0.7ml/kg and 1.4ml/Kg was found to be effective for male and female respectively with 54% fertilization rate, 43 % hatching rate. The positive response to synthetic hormone (ovaprim™) with considerable fertilization and hatching rate makes it possible to conduct the breeding program of this species commercially and the method can be applicable for commercial culture.

Sucuk, Turkish-Style Fermented Sausage: Evaluation of the Effect of Bioprotective Starter Cultures on Its Microbiological, Physicochemical, and Chemical Properties

Bio-protection is one of the most popular natural protection methods to control food safety and shelf life. Lactic acid bacteria, especially Lactobacilli strains, are used in the food industry for this purpose due to their probiotic properties and, accordingly, bioprotective properties. We aimed to investigate the role of the bacteriocin-producing lactic acid bacteria Lactobacillus sakei and Pediococcus acidilactici in inducing microbiological, physicochemical, and chemical changes in the Turkish-style fermented sausage sucuk. The effects of protective cultures were compared with those of commercial starter cultures consisting of Pediococcus pentosaceus + Staphylococcus carnosus; a non-cultured group was used as a control. L. sakei inoculation and, to a lower extent, P. acidilactici inoculation resulted in the rapid domination of lactic acid bacteria (LAB) in the environment, whereas commercially used starter cultures and the non-cultured group showed lower counts of LAB. Moreover, L. sakei and P. acidilactici succeeded in inhibiting pathogens including S. aureus, E. coli, and Enterobacteriaceae. The number of enterococci decreased notably in the L. sakei-inoculated sucuk samples; however, an increase was determined in the samples inoculated with P. acidilactici. On the other side, the effect of commercial starter cultures was not sufficient for the inhibition of food-borne pathogens in the sucuk samples. Consequently, the inoculation of protective cultures, particularly of L. sakei, can provide a considerable contribution to improving microbial quality and food safety, retarding lipid oxidation, and increasing proteolytic activities in sucuk without important changes in its sensory properties.

Bioeconomic analysis of deterministic and stochastic partial harvesting in the production of spring genetics tilapia variety restricted to minimum market sizes

A bioeconomic model was used for commercial tilapia culture to evaluate different partial harvest strategies. This study considered homogeneous and heterogeneous seeding sizes. The impact of one and two partial harvests was evaluated. In the first case 25% of the population was harvested (I), in the second 50% (II), in the third 25% and 25% (III), and in the fourth 50% and 25% (IV). Four minimum market sizes were considered: 350, 400, 450, and 500 g. The results indicated that a first partial harvest of 25% or 50% of the population as well as two partial harvests with a homogeneous seeding sizes generated the highest net benefits, with US$3954.32 and US$4303.52 at a minimum market sizes of 500 g. Mortality rate, mean water temperature, feed cost and product price were considered as sources of uncertainty and were simultaneously analyzed in the bioeconomic model using Monte Carlo analysis. An initial partial harvest of 25% of the population followed by two partial harvests with a homogeneous seeding sizes and a minimum market sizes of 500 g presented the lowest uncertainty and an expected loss of 32.84% and US$0.00, respectively. An initial partial harvest of 50% of the population as well as a partial harvest with a heterogeneous seeding sizes presented the lowest uncertainty (31.97%), while two partial harvests with a homogeneous seeding sizes presented the lowest expected loss of US$-2.09, in both cases with a minimum market sizes of 500 g. It provides relevant information to the producer for decision-making in the management of seeding and harvesting, to improve their economic, considering minimun market sizes.

Survey of trematodes in Manila clam Ruditapes philippinarum on the west coast of Korea: A preliminary study

The Manila clam Ruditapes philippinarum on the west coast of Korea harbors several digenetic trematodes. However, most studies in this region have been restricted to a few sampling sites and the current species designation of some trematodes is largely based on morphology, leaving the molecular phylogenetic position among the Digenea unsolved. Thus, we first provide both morphology and molecular phylogeny of some components in the trematodes community in the Manila clam based on a large-scale survey of 26 sites on the west coast, where well-developed tidal flats serve as large commercial clam culture beds. Our study revealed that the trematodes community in the clams consisted of at least 5 species that belong to 3 families (Himasthlidae, Gymnophallidae, Baccigeridae) and 1 superfamily (Monorchioidea). The life mode of the 5 different species included the metacercaria and sporocyst, with one species (Parvatrema duboisi) utilizing the clams as both the first and/or second intermediate host. Trematode infection prevalences were not evenly distributed among the study sites, although the reasons behind this are yet to be determined. Morphological identification was confirmed with the molecular analyses based on ITS and 28S rDNA; phylogenetic analysis also revealed that Cercaria pectinata infecting the clam gonad should be referred to as Bacciger bacciger hereafter. The present preliminary study provides a crucial baseline that could be further developed in a future study on the digenean trematodes community in the Manila clam.