PENGARUH KOMPOSISI MEDIA SUBSTRAT TERHADAP PERTUMBUHAN DAN HASIL KAILAN SISTEM BUDIDAYA AKUAPONIK

Budidaya sawi kailan sistem akuaponik diharapkan mendapat pertumbuhan dan produksi yang tinggi, oleh karena itu perlu didukung dengan memberikan media tanam yang baik. Salah satu media tanam yang bisa digunakan yaitu media substrat yang terdiri dari campuran antara pasir kerang, arang sekam padi, dan cocopeat. Penelitian ini bertujuan untuk mengetahui pengaruh komposisi media substrat dan untuk mengetahui komposisi media substrat yang terbaik untuk pertumbuhan dan hasil kailan sistem budidaya akuaponik. Penelitian ini dilaksanakan di lahan pertanian yang terletak di Jalan Kalimas Tengah Desa Kalimas, Kecamatan Sungai Kakap, Kabupaten Kubu Raya, Provinsi Kalimantan Barat. Penelitian ini berlangsung pada tanggal     16 Agustus – 12 Oktober 2022. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) 1 faktor yang terdiri dari 8 taraf perlakuan yang merupakan perbandingan persentase antara pasir kerang, arang sekam padi, dan cocopeat terdiri dari A = (5 : 75 : 20), B = (5 : 70 : 25),     C = (10 : 70 : 20), D = (10 : 65 : 25), E = (15 : 65 : 20), F = (15 : 60 : 25), G = (20 : 60 : 20), dan H = (20 : 55 : 25). Variabel yang diamati dalam penelitian ini yaitu tinggi tanaman, jumlah daun, luas daun, volume akar, berat segar bagian atas tanaman, dan berat kering bagian atas tanaman. Pelaksanaan penelitian meliputi persiapan tempat penelitian, persiapan instalasi akuaponik, persiapan media substrat, penyemaian, pindah tanam, pemeliharaan tanaman, dan pemanenan. Hipotesis yang diajukan dalam penelitian ini yaitu diduga terdapat pengaruh komposisi media substrat dan diduga terdapat salah satu komposisi media substrat terbaik untuk pertumbuhan dan hasil kailan pada sistem budidaya akuaponik.Hasil penelitian menunjukkan bahwa komposisi media substrat berpengaruh terhadap pertumbuhan, namun tidak berpengaruh terhadap hasil sawi kailan. Komposisi media substrat 20% pasir kerang, 60% arang sekam dan 20% cocopeat merupakan komposisi yang memberikan pertumbuhan tanaman kailan yang lebih baik dibanding perlakuan lainnya.Kata Kunci   : Akuaponik, Kailan, Media Substra

Genome rearrangements and megaplasmid loss in the filamentous bacterium Kitasatospora viridifaciens are associated with protoplast formation and regeneration

Filamentous Actinobacteria are multicellular bacteria with linear replicons. Kitasatospora viridifaciens DSM 40239 contains a linear 7.8 Mb chromosome and an autonomously replicating plasmid KVP1 of 1.7 Mb. Here we show that lysozyme-induced protoplast formation of the multinucleated mycelium of K. viridifaciens drives morphological diversity. Characterisation and sequencing of an individual revertant colony that had lost the ability to differentiate revealed that the strain had not only lost most of KVP1 but also carried deletions in the right arm of the chromosome. Strikingly, the deletion sites were preceded by insertion sequence elements, suggesting that the rearrangements may have been caused by replicative transposition and homologous recombination between both replicons. These data indicate that protoplast formation is a stressful process that can lead to profound genetic changes

Off the wall: characterisation and exploitation of a cell wall-deficient life style in filamentous actinomycetes

Almost all bacteria are enveloped by a cell wall that provides cellular protection. In this thesis I show that some filamentous actinomycetes have a surprising natural ability to adopt a cell wall-deficient life style. The formation of these newly identified S-cells is a transient morphological adaptation in response to hyperosmotic stress conditions. In contrast, prolonged exposure to cell wall-targeting antibiotics or osmotic stress leads to the formation of so-called L-form cells, which are mutants that can proliferate indefinitely without their cell wall. The exciting properties of L-forms were used to discover a new cell-wall biosynthetic enzyme and to study enzyme secretion in the absence of a cell wall.Microbial Biotechnolog

Stress-induced formation of cell wall-deficient cells in filamentous actinomycetes

The cell wall is a shape-defining structure that envelopes almost all bacteria and protects them from environmental stresses. Bacteria can be forced to grow without a cell wall under certain conditions that interfere with cell wall synthesis, but the relevance of these wall-less cells (known as L-forms) is unclear. Here, we show that several species of filamentous actinomycetes have a natural ability to generate wall-deficient cells in response to hyperosmotic stress, which we call S-cells. This wall-deficient state is transient, as S-cells are able to switch to the normal mycelial mode of growth. However, prolonged exposure of S-cells to hyperosmotic stress yields variants that are able to proliferate indefinitely without their cell wall, similarly to L-forms. We propose that formation of wall-deficient cells in actinomycetes may serve as an adaptation to osmotic stress

An alternative and conserved cell wall enzyme that can substitute for the lipid II synthase MurG

Microbial Biotechnolog

Stress-induced adaptive morphogenesis in bacteria

Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful pathogens.Microbial Biotechnolog

Off the wall: characterisation and exploitation of a cell wall-deficient life style in filamentous actinomycetes

Almost all bacteria are enveloped by a cell wall that provides cellular protection. In this thesis I show that some filamentous actinomycetes have a surprising natural ability to adopt a cell wall-deficient life style. The formation of these newly identified S-cells is a transient morphological adaptation in response to hyperosmotic stress conditions. In contrast, prolonged exposure to cell wall-targeting antibiotics or osmotic stress leads to the formation of so-called L-form cells, which are mutants that can proliferate indefinitely without their cell wall. The exciting properties of L-forms were used to discover a new cell-wall biosynthetic enzyme and to study enzyme secretion in the absence of a cell wall

Off the wall: characterisation and exploitation of a cell wall-deficient life style in filamentous actinomycetes

Almost all bacteria are enveloped by a cell wall that provides cellular protection. In this thesis I show that some filamentous actinomycetes have a surprising natural ability to adopt a cell wall-deficient life style. The formation of these newly identified S-cells is a transient morphological adaptation in response to hyperosmotic stress conditions. In contrast, prolonged exposure to cell wall-targeting antibiotics or osmotic stress leads to the formation of so-called L-form cells, which are mutants that can proliferate indefinitely without their cell wall. The exciting properties of L-forms were used to discover a new cell-wall biosynthetic enzyme and to study enzyme secretion in the absence of a cell wall

Genome Sequence of the Filamentous Actinomycete Kitasatospora viridifaciens

The vast majority of antibiotics are produced by filamentous soil bacteria called actinomycetes. We report here the genome sequence of the tetracycline producer "Streptomyces viridifaciens" DSM 40239. Given that this species has the hallmark signatures characteristic of the Kitasatospora genus, we previously proposed to rename this organism Kitasatospora viridifaciens.Microbial Biotechnolog