Characteristics and Activity Anti Qourum Sensing Bacillus spp. Isolated from Penaeus vannamei Shrimp Ponds

Certain strains of V. parahaemolyticus carry a gene that encodes a toxin that causes Acute hepatopancreatic necrosis disease (AHPND) in P. vannamei. AHPND attacks shrimp post larvae within 20-30 days after stocking causing up to 100% mortality. The expression of these virulent genes is controlled by the quorum sensing system. This system is inhibited by an anti-quorum sensing (AQS) mechanism. Several Bacillus strains have AQS mechanism by producing AHL-Lactonase enzyme. Therefore, this study aimed to obtain Bacillus spp. having AQS activity for controlling AHPND. The study was conducted from isolation and selection of Bacillus isolates, as well as determination of AQS activity. From 22 samples consisting of shrimp intestines, water and pond sediment samples, a total of 151 isolates of Bacillus spp. were isolated. The screening test for AQS activity obtained 11 isolates that showed AQS activity on Cromobacterium violaceum. Determination of violacein pigment in liquid cultures of C. violaceum showed the index value of the pigment formation was between 0.025-0.166 and 0.026-0.567 at 24-hour and between 48-hour incubations, respectively. The quantitative analysis of violacein production showed that there were six isolates of Bacillus could inhibit the pigment production more than 75%. The isolates were identified as Bacillus cereus (four isolates), Bacillus thuringiensis (one isolate), and Bacillus velezensis (one isolate), respectively. The molecular analysis had confirmed that the isolates have aiiA genes encoding AHL-lactonase enzyme. These Bacillus isolates have potential application for controlling AHNPD disease.

Pendekatan Kolaboratif dalam Menangani Konflik Spasial Kawasan Pesisir di Pantai Selatan Yogyakarta

Title: A Collaborative Approach to Handling Coastal Spatial Conflicts in Yogyakarta Southern Coast Yogyakarta's southern coastal ecosystem is facing increasing impacts from fisheries, aquaculture, tourism, energy production, shipping, pollution, climate change and other stressors. This paper discusses the importance of collaborative planning, more than community-based in coastal tourism areas as well as mangrove forest conservation areas, as well as environmental stressors in the form of shrimp ponds. The purpose of this paper is to analyze the understanding of the type of planning approach that is most appropriate, namely collaborative in areas that have spatial conflicts. The method used in this paper is a literature study which describes the theory, findings, and other research materials obtained from reference material to be used as a research basis by compiling a clear framework from the formulation of the problem to be studied. coupled with field observations. The author then provides a review, summary, and dialogue about the theory which is then used to build a relevant theoretical framework. Literature references used are related to collaborative planning and coastal tourism. Based on the discussion that has been done, it can be concluded that to overcome spatial conflicts in the southern coastal tourism area of ??Yogyakarta, this type of planning with a collaborative approach is the most appropriate to be applied wherein the process involves stakeholders with the ultimate goal of a collective agreement for all parties and with a sustainable perspective.

Dynamic model of dissolved oxygen in intensive concrete pond of white leg shrimp (Litopenaeus vannamei) in Bomo Village, East Java

This study is to understand a simple model of dissolved oxygen (DO) and other water quality factors that affect it in two seasons in intensive white leg shrimp ponds. Water quality parameters in the dry and rainy seasons in several ponds were sampled daily, including temperature, pH, (DO), salinity, twice a week, including ammonium, nitrite, nitrate, orthophosphate, total alkalinity, and total bacteria. Besides daily, dissolved oxygen is also measured before the harvest every two hours by using dark bottles and light bottles. Pond water quality parameters are still suitable for white shrimp culture. Daily DO shrimp ponds form a polynomial regression model. DO in light bottles constructed a quadratic regression model, DO in dark bottles created a linear regression pattern, with a DO reduction rate of 0.6338 mg−l per hour. During one of the shrimp cultures, the DO model showed an inverse quadratic equation with the lowest oxygen solubility level on day 57. DO was positively correlated with changes in salinity and transparency and negatively related to ammonium, nitrate, phosphate, total alkalinity, and total bacteria count.

Physical characteristics of effervescent tablet probiotics in various concentration of tapioca coatings

RICA (Research Institute for Coastal Aquaculture) Maros in South Sulawesi has developed 5 probiotic preparations, namely RICA-1, RICA-2, Rica-3, RICA-4 and RICA-5 in liquid form to improve shrimp farming in ponds. In practice, the use of liquid probiotics has been very optimal but the distribution is constrained because of its liquid form. For this reason, microencapsulation of liquid probiotics is carried out to protect from the external environment and maintain the viability of probiotic cells in the encapsulated matrix. The purpose of this study was to determine the physical properties of probiotic effervescent tablets using tapioca coating with different concentration variants (10 and 20%) with four effervescent tablet formulas. The results showed that the pH of the probiotic effervescent tablet Formula 3 with a coating concentration of 10% tapioca had a neutral pH compared to all existing formulas. However, the pH for probiotic effervescent tablets produced by all formulas can still be applied to shrimp ponds. Formula 4 with 10% tapioca coating has a mean weight and hardness that is close to the standard as well as a disintegration time that meets the specified standard of tablet physical properties. Meanwhile, the tablet friability value was met by Formula 3 with a concentration of 10% tapioca coating. It can be concluded that the best formula that meets the standard physical properties of tablets is Formula 4 with 10% tapioca coating. The probiotic effervescent tablet with tapioca coating has a weakness in the hardness value which causes the average weight to be not uniform. These results indicate that tapioca coating is not suitable for use as a coating for probiotic effervescent tablets.

Optimization of Paddle Wheel Aeration, a preliminary study of Integrated Smart Aquaculture System

The paddlewheel aerator is one of the supporting facilities in the intensive aquaculture pond system. Assuming all the land uses an intensive cultivation system, more than two million paddlewheels worth more than 10 trillion will be needed by 2024. Currently, all paddlewheels are produced abroad or imported. This is very unfortunate considering the vast market potential. This paper discussed a preliminary study of developing paddlewheel aeration for shrimp ponds using an integrated intelligent aquaculture system to support intensification. Two paddlewheel aerators with modifications in the gearbox have been successfully installed. Based on the observation and user’s testimony, the newly installed paddlewheel was quite good, the sound of the motor was smooth, then the flow range was longer, the coverage area was more expansive than the existing waterwheel. This research would be a foundation for intelligent paddlewheel aeration design that can be developed domestically to support local industry in Indonesia.

Keep or Lose It: Mirroring Tana Sangkol in Madura Contemporary Literature

Ancestral land or tana sangkol in Madura is a significant material asset possessed by the Madurese people, with attached social and cultural values that link the living and the dead. Massive development on the island, however, has seen people selling their tana sangkol to foreign investors for conversion into shrimp ponds and hotels. This study aimed to analyze tana sangkol’s representation in three short stories, “Anak Cangkul,” “Kutukan Tanah Leluhur,” and “Tanah Warisan,” by Zainul Muttaqin, an author from Sumenep, Madura. The discussion mainly focused on the dramatic contribution of poverty to the sale of tana sangkol to investors, an act that is believed to bring bad luck to the sellers. Furthermore, tana sangkol epitomizes pride to the Madurese people, making them more willing to resist the intrusion of foreign investment. A qualitative research method with a close reading technique was applied and the data were analyzed using the post-colonial ecocriticism theory of Graham Huggan and Helen Tiffin. The results showed that there has been a shift in how the Madurese view their tana sangkol, with them no longer regarding it as sacred ancestral land. Moreover, it is considered to have social and cultural contexts due to its close relationship with the Madurese people’s identity. Meanwhile, the oppression toward farmers is seen as structural and hierarchical.

Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds

Rusmana I, Isramilda, Akhdiya A. 2021. Characteristics of anti-Vibrio harveyi compounds produced by Bacillus spp. isolated from shrimp ponds. Biodiversitas 22: 4872-4879. Pathogenic Vibrio spp. such as Vibrio vulnificus, V. alginolyticus, V. fluvialis, V. anguillarum, and V. harveyi caused shrimp diseases. The application of bacterial probiotics can control the growth of pathogenic Vibrio in shrimp. Bacillus spp. can produce antimicrobial compounds that inhibit the growth of pathogenic Vibrio spp. Isolation of Bacillus from several pond water samples, pond sediment, and shrimp intestines was successfully collected 175 isolates of Bacillus spp. Three isolates, i.e., Ltw54, Lts36, dan Lts40 had a high inhibitory index and stability in inhibiting the growth of Vibrio harveyi. Verification assay showed that Bacillus sp. Lts40 had the highest antimicrobial activity. The competition assay showed that Bacillus sp Lts40 isolates inhibited the growth of V. harveyi up to 81,8%. The antimicrobial compound produced by Bacillus sp. Lts40 was stable at the pH range of 3-11 and remained stable after heating at 100ºC for 20 minutes. The purification results using the chromatographic filtration technique showed that the protein fraction with a molecular weight of 47,38 kDa effectively inhibited V. harveyi growth. Bacillus sp. Lts40 isolate has potential application as a probiotic agent in shrimp ponds to control the growth of V. harveyi that causes luminous vibriosis diseases and the antimicrobial substance is potentially to be developed and produced as an anti-V. harveyi product that can be applied in a shrimp hatchery.

Effect of Mangrove Cover on Shrimp Yield in Integrated Mangrove-Shrimp Farming

In recent decades, mangroves have been seriously devastated by shrimp farming development in the Vietnamese Mekong Delta. As a result, integrated mangrove-shrimp farming has emerged as a potential solution to culture shrimps and protect mangroves. The present study aims to understand whether mangrove-to-pond cover ratios influence shrimp yields in an integrated mangrove-shrimp farming system. Five integrated mangrove-shrimp ponds in the Tam Giang Commune, Nam Can District, Ca Mau Province (Southern Vietnam) were chosen for this study. The study estimated that the mangrove-to-pond cover ratios ranged from 42.00 % to 72.50 %. The total shrimp yield per year (kg.ha-1 yr-1 ) was generally high, ranging from 76.62 to 249.09 (including 37.93 to 108.64 for the black tiger shrimp (Penaeus monodon Fabricius, 1798), and 38.69 to 140.45 for other shrimps, namely Penaeus indicus Milne Edwards, 1837, Penaeus merguiensis de Man, 1888, Metapenaeus ensis (De Haan, 1844), and Metapenaeus lysianassa (de Man, 1888)). Moreover, a strong positive correlation between the mangrove-to-pond cover ratios and the shrimp yields were observed (r > 0.71, P < 0.05). In conclusion the mangrove-to-pond cover ratios have a direct impact on the total shrimp yield. The mangrove-to-pond cover ratios should be 50 % to enhance shrimp yields in this system.

Waterbirds roosting on gas drilling platforms in Mahakam Delta, East Kalimantan: the Unexpected Impact of Landscape Transformation

Since 2014 some offshore gas platforms operated by Pertamina Hulu Mahakam near Mahakam Delta has been used by hundreds of egrets as roosting sites, causing nuisance to the platform and hampering the duty of workers/operator. The objective of this paper was to analyse the situation of the waterbirds’ nuisance, analyse the possible causes, and provide some recommendations. Field visits were conducted in August 2019 and February 2020 to three unmanned platforms (Ax, D, C) that suffered the most from the bird roost. Birds that infested the platforms were identified as great egret and intermediate egret, both are very similar in appearance and ecological requirements. The maximum number of egrets visiting C-Platform (the worst platforms) was 671 birds. These birds roost at night in the platform and leave the platform in the morning to forage for fish, eel, and shrimps in the wetlands of Mahakam Delta, about 2-4 km from the platform. The root cause of the infestation was believed to be the landscape transformation in the Mahakam Delta. Mangrove forest has been diminished and heavily converted into shrimp-ponds. The egrets’ foraging areas became ubiquitous, while the roosting/nesting site greatly decreased, forcing the egrets to roost on gas platforms. In the short-medium term, platforms need to be managed as bird tolerated-zone and bird-free zone (using deterrent), while in the long term, land-use in Delta Mahakam need to be restored.