Judul: Isolation, Selection, and Application  of Methylotroph Bacteria with Mycorrhizae and Inorganic Fertilizers on the Growth  of Sweet Corn (Zea mays saccharata Sturt)
Abstrak: Beberapa dari mikrob yang menarik untuk dikaji sebagai pupuk hayati adalah bakteri methylotroph dan mikoriza. Penelitian ini bertujuan mengisolasi, menyeleksi, dan mengidentifikasi bakteri methylotroph, membuat propagul mikoriza dengan perbanyakan mikoriza, dan mengkaji pengaruh pemberian bakteri methylotroph, mikoriza, serta dosis pupuk NPK terhadap pertumbuhan tanaman jagung manis. Penelitian menggunakan Rancangan Acak Lengkap (RAL) Faktorial yang terdiri dari tiga faktor. Faktor pertama yaitu dosis pupuk NPK dengan 3 taraf (D0: 0%, D1: 50%, D2: 100% dosis rekomendasi), faktor kedua adalah pemberian bakteri methylotroph dengan 2 taraf (B0: tanpa bakteri, B1: diberi bakteri), dan faktor ketiga yaitu pemberian propagul mikoriza dengan 2 taraf (M0: tanpa propagul, M1: diberi propagul). Data dianalisis secara statistik menggunakan ANOVA pada taraf 5% dan diuji lanjut dengan DMRT. Hasil penelitian menunjukkan bahwa bakteri methylotroph berhasil diisolasi, diseleksi, dan identik dengan Methylophilus methylotrophus ICBB 9931 dengan kemampuan membantu perkecambahan sebesar 64%. Perbanyakan mikoriza menghasilkan propagul dengan derajat kolonisasi sebesar 91,1% dan kepadatan spora sebesar 46,5/20 g media. Hasil percobaan lapang menunjukkan bahwa perlakuan 100% dosis rekomendasi NPK dengan diberi mikoriza secara tunggal (D2B0M1) memiliki nilai terbaik pada parameter tinggi tanaman, bobot basah akar, serta bobot kering tanaman dan akar. Pemberian bakteri Methylophilus methylotrophus ICBB 9931 tidak selalu memberikan hasil yang positif pada tanaman diduga karena kurangnya bahan organik., Some interesting microbes to be study as biofertilizers are methylotroph bacteria and mycorrhizae. This study aims to isolate, select, and identify methylotroph bacteria, produce mychorrhizae propagules with mycorrhizae propagation, and examine the effect of giving methylotroph bacteria, mycorrhizae, and doses of NPK fertilizer on the growth of sweet corn plants. The study used a completely randomized design (CRD) factorial consist of three factors. The first factor was the dose of NPK fertilizer consist of 3 levels (D0: 0%, D1: 50%, D2: 100% recommended dose), the second factor was the addition of methylotroph bacteria consist of 2 levels (B0: without bacteria, B1: given bacteria), and the third factor is the addition of mycorrhizal propagules consist of 2 levels (M0: without propagules, M1: given propagules). Data were analyzed statistically using ANOVA at the 5% level and it was further tested with DMRT. The results of the study succeeded in isolating and selecting the methylotroph bacteria which were identical to Methylophilus methylotrophus ICBB 9931 with the ability to promote seed germination rates by 64%. Mycorrhizal propagation produced propagules with a colonization degree of 91.1% and a spore density of 46.5/20 g media. The results of the field experiments showed that the 100% recommended dose of NPK treatment with mycorrhizae in particular (D2B0M1) had the best values for the parameters of plant height, fresh weight of roots, and dry weight of plants and roots. The addition of Methylophilus methylotrophus ICBB 9931 does not always give positive results to plants presumably due to the lack of organic matter.
Keyword: biofertilizers, methanol utilizing bacteria, seed coating, seed germination test