I Made Samudra
Balai Besar Penelitian dan Pengembangan Bioteknologi dan Sumberdaya Genetik Pertanian, Jl. Tentara Pelajar No. 3A, Bogor 16111 Telp. (0251) 8337975

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Journal : BERITA BIOLOGI

EKSPLORASI DAN KARAKTERISASI ENTOMOPATOGEN ASAL BERBAGAI INANG DAN LOKASI [Exploration and Characterization of Entomopathogenic from Various Host and Location] Priyatno, Tri Puji; Samudra, I Made; Manzila, Ifa; Susilowati, Dwi Ningsih; Suryadi, Yadi
BERITA BIOLOGI Vol 15, No 1 (2016)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3631.714 KB) | DOI: 10.14203/beritabiologi.v15i1.2859

Abstract

Microbial groups of entomopathogenic (fungi and bacteria) had been reported causing insect mortality. The aim of the study was to explore and characterized entomopathogenic from various host and locations. Fungal identification at genus and species level was caried out based on conidial morphology, hyphal growth, conidiophore and colony color; whilst for bacterial identification was based on standard Bergey’s manual for determinative bacteria. Sixteen entomopathogenic isolates that consisted of fungal and bacteria have been collected and preserved for further characterization. Of the 16 entomopathogen collected samples, five fungal genera was found i.e. Paecilomyces; Metarhizium, Beauveria, Hirsutella; and Cordyceps. Seven isolates belonging to six fungal isolates, and one bacterial isolate had been identified based upon ITS and 16S rDNA sequences, respectively. We confirmed that 6 fungal isolates belong to species of Paecilomyces reniformis, B. bassiana, M. anisopliae, M. anisopliae var acridum, Hirsutella thomsonii. One isolate of red pigmented bacteria Sm201102 have been identified was belonging to species Seratia marcescence. It was also obtained two fungal isolates from different host (spider and beetle) which confirmed by morphological character belong to Cordyceps sp.
PROTEIN TOKSININSEKTISIDAL DARI BAKTERI PATOGEN SERANGGA Photorhabdus luminescens HJ Akhdiya, Alina; Pratiwi, Etty; Samudra, I Made
BERITA BIOLOGI Vol 8, No 6 (2007)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (377.996 KB) | DOI: 10.14203/beritabiologi.v8i6.828

Abstract

Photorhabdus luminescens HJ is an entomopathogenic bacterium that has a high toxicity against Tenebrio molitor larvae.Toxicity assay of crude extra cellular protein precipitated using ammonium sulphate showed that the highest toxin activity was found in 70 % saturation. Purification of the toxin using Hi Prep 16/60 Sephacryl S-200 HR column exhibited one fraction of toxic protein and three fractions of non-toxic protein. Mortality of T. molitor larvae treated with 19.2 nanogram of toxic fraction was up to 80%. Denatured protein analysis using sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that the toxic fraction was composed of three proteins, which were 19.5, 42, and 66 kDa respectively. Based on toxin activity bioassay, this toxin type was an injectable toxin and presumably classified as Mcf toxin.
KARAKTERISASI BAKTERI PENGHASIL ASAM INDOL ASETAT DAN PENGARUHNYA TERHADAP VIGOR BENIH PADI Lestari, Puji; Suryadi, Yadi; Susilowati, Dwi Ningsih; Priyatno, Tri Puji; Samudra, I Made
BERITA BIOLOGI Vol 14, No 1 (2015)
Publisher : Research Center for Biology-Indonesian Institute of Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/beritabiologi.v14i1.1859

Abstract

The ability to produce indole acetic acid (IAA) by endophytic bacteria is one of the basic criteria for the use of bacteria as plant growth promoter agent which is essential for the agricultural production.The objectives of this study were to evaluate the ability of 17 bacterial isolates to produce IAA and its effect on improvement of rice seed germination and molecular identification of the selected isolates based on the 16S rRNA gene. The IAA content was determined using Salkowski method measured by spectrophotometer UV-Vis and the effect of endophytic bacteria inoculation on seed germination was done by in vitro assay. Sequences of the selected isolates 16S rRNA amplified by PCR were analyzed the homology against bacterial 16S rRNA database in Genebank. IAA values ranged from 6.632 to 50.053 mg/L with the highest IAA production shown by isolate 6KJ which was followed by 4PB (41.807 mg/L). Bacterial IAA increased rice seed vigor significantly compared to control. However, bacterial inoculation with different concentrations of IAA did not significantly affect the growth of rice plants. Based on the IAA and its effect on seed vigor, 6KJ, 4PB and 2KB were selected for molecular identification. Results showed that the three isolates belonged to Bacillus genus, 6KJ as B. aryabhattai, 4PB belonging to B. cibi and 2KB having 97% homology with B. marisflavi. Further evaluation of the selected endophytic isolates producing IAA is necessary to be carried out to explore their potency as a source of hormone to promote plant growth.