Abstract. Ayuningrum D, Sabdaningsih A, Jati OE. 2021. Screening of actinobacteria-producing amylolytic enzyme in sediment from Litopenaeus vannamei (Boone, 1931) ponds in Rembang District, Central Java, Indonesia. Biodiversitas 22: 1819-1828. Coastal environments are dynamic places where various activities such as aquaculture take place. Waste from intensive aquaculture contains high amounts of organic material that negatively affect the pond system as well as the surrounding environment. Bioremediation using hydrolytic enzymes from microbes has been widely used as an alternative to remove organic waste because of its lower economic cost and more efficient. Microbes such as Gram-positive actinobacteria are widely known as enzyme producers. This research aimed to isolate actinobacteria from Litopenaeus vannamei pond sediment, to purify and characterize the actinobacteria based on morphological appearance, to conduct screening of amylolytic activity, and to identify the species of actinobacteria through 16S rDNA amplification as well as to construct their phylogenetic tree. Sampling was done in Rembang District, Central Java, Indonesia, with 5 sampling stations consist of 14 sampling points. Thirty-eight pure axenic cultures of actinobacteria were successfully isolated using two different media, namely IM6 and IM8. The IM8 medium promoted the most growth of 24 isolates rather than on the IM6 with only 14 isolates. Based on morphological appearance, most isolates belonged to Streptomyces-like actinomycete bacteria as many as 30 isolates and the rest 8 isolates belonged to mycelium-forming non-Streptomyces actinomycete bacteria. The screening results of amylolytic activity showed that all of the 38 actinobacteria formed halo zone with amylolytic index between 1.31-5.29. Top five highest amylolytic index was found in isolates SA4.1 (IM6), SD1.3 (IM8), SC3.3 (IM8), SC3.3 (IM6) and SC3.2 (IM8). The isolate SC3.3 (IM8) according to BLAST homology, showed a 98% similarity with Streptomyces atacamensis C60. Further research is needed to investigate the potential of isolate SC3.3 (IM8) to reduce the BOD level in the aquatic system as a bioremediator candidate.

Pesisir Mangunharjo di Kecamatan Tugu merupakan kawasan produktif baik untuk ekowisata mangrove, industri maupun lokasi budidaya perikanan. Sungai Beringin menjadi media terangkutnya berbagai sampah termasuk plastik dari kawasan pemukiman di hulu menuju ke hilir. Plastik tersebut akan menjadi mikroplastik yang memberikan dampak berbahaya bagi pencernaan biota perairan serta berbahaya apabila dikonsumsi oleh manusia. Tujuan dari penelitian ini adalah mengetahui bentuk, jenis dan perbedaan kelimpahan mikroplastik pada sedimen. Lokasi penenlitian ditentukan secara purposive sampling sebanyak tiga stasiun, yaitu Stasiun I (pantai), Stasiun II (sungai) dan Stasiun III (mangrove). Setiap stasiun diambil sampel secara random sampling sebanyak tiga kali. Hal pertama yang dilakukan adalah mengestraksi mikroplastik, selanjutnya menganalisis dan mengidentifikasinya. Langkah selanjutnya dilakukan uji FT-IR (Fourier transform infrared) spectroscopy untuk mengetahui senyawa kimia mikroplastik tersebut. Hasil penelitian menunjukan jenis mikroplastik yang ditemukan berupa fiber, fragmen, film dan pelet. Kelimpahan mikroplastik pada sedimen rata-rata berkisar 3.584-8.106,67 partikel/m3. Analisis statistik menghasilkan nilai signifikan (α < 0,05)  menandakan bahwa adanya perbedaan kelimpahan mikroplastik setiap kawasan.

Sungai Banjir Kanal Barat Semarang merupakan sungai dengan daerah padat pemukiman yang menyumbang suplai material organik maupun anorganik. Hal ini dapat menyebabkan pencemaran di perairan tersebut. Limbah dapat mempengaruhi kualitas perairan dan biota di dalamnya. Tujuan dari penelitian adalah untuk mengetahui hubungan antara kandungan bahan organik sedimen dengan kelimpahan makrozoobenthos, hubungan antara tekstur sedimen dengan kandungan bahan organik sedimen, serta hubungan antara tekstur sedimen dengan kelimpahan makrozoobenthos di muara dan sungai Banjir Kanal Barat, Semarang. Penelitian ini dilaksanakan pada bulan Maret - April 2018 dengan menggunakan metode kuantitatif. Penentuan lokasi sampling menggunakan purposive sampling yang terdiri dari 4 stasiun. Metode analisis statistik yang digunakan adalah uji normalitas, korelasi, regresi. Makrozoobenthos yang didapatkan adalah Nereis, Nephthys, Melanoides, Cerithium, Pomacea, Dreissena, dan Corbicula. Fraksi liat dan kandungan bahan organik memiliki hubungan yang positif dengan nilai korelasi r = 0,893. Fraksi liat dengan kelimpahan makrozoobenthos memiliki hubungan yang positif dengan nilai korelasi r = 0,906. Hal ini sama dengan kandungan bahan organik sedimen dengan kelimpahan makrozoobenthos juga memiliki hubungan yang positif dengan nilai korelasi r = 0,928. Semakin besar kandungan bahan organik sedimen dan makrozoobenthos. Kualitas perairan berdasarkan indeks keanekaragaman di stasiun IV sebesar  1,2 yang tergolong tercemar sedang. Sedangkan pada stasiun I, II dan III dengan nilai 0,15; 0,15 ; 0,93 termasuk tercemar berat.  Banjir Kanal Barat Semarang is a river with densely populated areas that contribute to the supply of organic and inorganic materials. This can cause pollution in these waters. Waste can affect the quality of water and biota in it. The purpose of this study was to determine the relationship between sediment organic matter with abundance of macrozoobenthos, the relationship between sedimentary texture and organic sediment materials, as well as the relationship between sedimentary texture and abundance of macrozoobenthos in estuaries of Banjir Kanal Barat, Semarang. This research was conducted in March - April 2018 using kuantitative method. Kinds of macrozoobenthos was found from genus Nereis, Nephthys, Melanoides, Cerithium, Pomacea, Dreissena, and Corbicula. Determination of the sampling location using purposive sampling method. The clay fraction and the abundance of sediment organic matter have a positive relationship with the correlation value r = 0.893. The clay fraction with abundance of macrozoobenthos has a positive relationship with the correlation value r = 0.906. This is the same as the abundance of organic sediment material with abundance of macrozoobenthos also has a positive relationship with the correlation value r = 0.928. the greater the percentage of clay, the more abundant the organic matter of sediment and makrozoobenthos.

Enzymes are catalysts that can increase the reaction time of a biochemical process. Hydrolytic enzymes have a pivotal role in degrading organic waste in both terrestrial and aquatic environments. The aims of this study were (1) to investigate the ability of actinobacteria isolated from Litopenaeus vannamei pond sediment to produce proteolytic and lipolytic enzymes, (2) to identify promising candidates using 16S rRNA gene amplification, and (3) to construct a phylogenetic tree based on the 16S rRNA genes. A skim milk agar medium was used in the preliminary experiment of the proteolytic assay, and a Tween 20/80 medium was used in the lipolytic assay. Fifteen and 20 (out of 40) actinobacterial isolates showed great potential for proteolytic and lipolytic activities, respectively. Furthermore, four actinobacteria isolates produced both enzyme types with proteolytic and lipolytic index scores of 1–6.5. The most promising candidates were SA 2.2 (IM8), SC 2.1 (IM6), SD 1.5 (IM6) and SE 1.1 (IM8). BLAST homology results showed a high similarity between the actinobacteria isolates and Streptomyces verucosisporus, S. mangrovicola, S. barkulensis and Nocardiopsis lucentensis, respectively. Therefore, actinobacteria from Litopenaeus vannamei pond sediment are high-potential proteolytic and lipolytic enzyme producers.

ABSTRAK Kerang hijau merupakan jenis hewan bertubuh lunak yang hidup menetap (sessile) dan mendapatkan makanan dengan menyaring (filter feeder). Hal ini mengakibatkan banyak mikroorganisme yang terakumulasi ke dalam tubuh kerang hijau, salah satunya yaitu kelompok bakteri Coliform. Bakteri Coliform dibagi menjadi dua yaitu fecal Coliform dan non fecal Coliform. Fecal Coliform berasal dari limbah kotoran hewan dan manusia contoh bakteri E. coli. Keberadaan bakteri E. coli di luar tubuh digunakan sebagai indikator sanitasi makanan dan minuman apakah tercemar atau tidak. Kondisi perairan Morosari mengalami penurunan kualitas air, hal tersebut disebabkan oleh limbah domestik penduduk yang langsung dibuang ke bantaran sungai. Hal ini memungkinkan adanya cemaran mikroba yang dapat membahayakan kesehatan seperti bakteri. Menurut SNI 01 7388 2009 nilai MPN bakteri E. coli untuk Mollusca, Crustacea, dan Echinodermata segar adalah <3/g. Tujuan dari penelitian ini yaitu mengetahui kelimpahan  bakteri E. coli pada kerang hijau dan untuk membandingkan kelimpahan bakteri E. coli dengan baku mutu SNI. Penelitian ini dilaksanakan pada bulan Juli 2019. Pengambilan sampel terdiri 9 sampel kerang hijau (kecil <60 mm, sedang 61-70 mm dan besar >70 mm) dengan 3 ekor kerang pada masing masing ukuran. Metode MPN merupakan  metode digunakan untuk analisis bakteri Coliform dan E. coli. Hasil Uji MPN yang didapat yaitu > 1100 MPN/g pada semua sampel. Kesimpulannya berdasarkan hasil uji MPN diperoleh nilai MPN yaitu >1100 MPN/g, hasil tersebut menunjukkan bahwa kelimpahan bakteri E. coli pada kerang hijau melebihi baku mutu yang ditetapkan berdasarkan SNI 01-7388 2009. ABSTRACTGreen mussels are the type of mollusk that live permanently (sessile) and gets food by filtering (filter feeder). It causes many microorganisms accumulating into the body of green mussels, one of them is a group of Coliform bacteria. Coliform bacteria are divided into two, namely fecal and non-fecal Coliform.Coliform is derived from the waste of animal and human i.e. E. coli bacteria. The existence of E. coli bacteria outside the body is used as an indicator of sanitation for food and drink.The condition of Morosari waters has decreased, it’s caused by the domestic waste of resident which is discharge into the riverbank directly.This allows microbial contamination that can endanger health such as bacteria. According to SNI 01-7388-2009 MPN value from E. coli bacteria for Mollusks, Crustaceans, and Echinoderms is <3/g.. The purpose of this study was to determined the abundance of E. coli bacteria in green mussels and to compared the abundance of E. coli bacteria with the quality standards of SNI. The research was conducted in July 2019. The samples were consisted of 3 types size of green mussels,  small (<60 mm), medium (61-70 mm) and large (>70 mm) and 3 mussels selcted from the each size. MPN method was used for the analysis of Coliform and E. coli bacteria. MPN test result was > 1100 MPN/g on all samples.The result showed,that the abundance of E. coli bacteria in green mussels exceed the quality standard based on SNI 01-7388 2009.