Protein Toksininsektisidal Dari Bakteri Patogen Serangga Photorhabdus Luminescens Hj [Insecticidal Toxin Protein Produced by Enthomopathogenic Bacterium Photorhabdus Luminescens Hj]

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 Morfologi Tiga Genus Serangga Penggerek (Lepidoptera: Pyraloidea)

Morphological characterization of three genere of insect borer (Lepidoptera: Pyraloidea). The objective of the research was to characterize the morphological differences of insect borers between Genus Etiella (Pyralidae: Phycitinae), Scirpophaga (Crambidae: Schoenobiinae), and Ostrinia (Crambidae: Pyraustinae). Observed characters were based on external morphology and genitalia. The result showed that Crambidae has praecinctorium in the tympanic organs, while lack of in Pyralidae. Phycitinae had chaetosema, proboscis, cubital pecten and the elongated forewing. Pyraustinae was lack of chaetosema and their forewings are wide towards termen. Whereas, Schoenobiinae had chaetosema with elongated forewing. Etiella had scales on antemedial area and their veins M2-M3 are fused. Forewing of Ostrinia had 11 veins and the corpus bursae shape was round irregular. Forewing of Scirpophaga had 12 veins, anal hair tuft, coremata, and the corpus bursae is round. The main characteristics used in identification at family and subfamily level were the praecinctorium, chaetosema, the shape of the forewings, proboscis, and cubital pecten. Whereas at genus level; anal hair tuft, coremata, and shape of the corpus bursae formed the basis of characterization. The morphological characterization was used to make the key identification of insect borers in Indonesia

Host Preference Fruit Flies Bactrocera Carambolae (Drew & Hancock) and Bactrocera Dorsalis (Drew and Hancock) (Diptera: Tephritidae)

Host plant preference amongst several fruit species was studied for two fruit fly species i.e. Bactrocera carambolae (Drew & Hancock) and Bactrocera dorsalis (Drew & Hancock), which both belong to B. dorsalis species complex. Both fruit fly species are known to be polyphagous and cause significant economic losses as pests of fruit crops. The aim of this research was to assess the host range of these major pests in Indonesia. The research was conducted at the Entomology Laboratory and Insect Specimen Collection Laboratory, Indonesian Center for Agriculture Biotechnology and Genetic Resource Research and Development, Bogor, West Java, Indonesia from June 2011 to March 2012. Comparative host preference for both species was studied with regard to malaya varieties of star fruit (Averrhoa carambolae), manalagi varieties of mango (Mangifera indica), guava aka water apple (Psidium guajava), citra water guava (Eugenia aquae), Jamaica bol guava (Eugenia malaccenensis), and california papaya (Carica papaya). Our results suggest the strongest preference for malaya star fruit by B. carambolae followed by manalagi mango; and for california papaya followed by manalagi mango by B. dorsalis. The study also found that welahan variety star fruit is least preferred by both species of fruit fly

Characterization of Profenofos Degrading Bacteria

Bioremediation is an inexpensive, easy, and safe technology to rehabilitate agricultural land which is highly polluted with pesticides. The aims of this study were to isolate and characterize profenofos degrading bacteria isolated from Pangalengan soils. The isolation step was carried out by using spread plate method on Nitrate Mineral Salts (NMS) medium containing 100 ppm profenofos. The isolates were selected based on hypersensitive response (HR) and hemolytic test, and ability of the isolates to use and degrade profenofos. The selected isolates were characterized based on the sequence of 16 rRNA and detection of the α and β subunits of terminal deoxygenase and naphtalene dioxygenase encoded genes. Three isolates (CN26, CN44, and CN86), which could use profenofos as the exclusive C source, could degrade more than 86.75% profenofos containing growth medium. Based on the 16S rRNA sequences, the three isolates were closely related to Stenotrophomonas maltophilia (99%), Comamonas terrigena (99%), and Pseudomonas sp. (80%). Pseudomonas CN44 consistenly showed high profenofos degradation activity of up to 91.2% when grown on NMS medium (pH 6.8) for 72 hours. β subunit dioxygenase encoding gene of the isolates were detected using primers Rf2-F/Rf2-R, but optimation of PCR is still needed to detect the α subunit of the gene. Naphtalene dioxygenase gene was detected only from Pseudomonas CN44 using the primer pair 301f/1099r. Based on its biodegradation capability and molecular characteristics, Pseudomonas CN44 is very potential to be developed as a bioremediating agent of profenofos

Karakterisasi dan Identifikasi Isolat Bakteri Endofitik Penghambat Jamur Patogen Padi

Disease caused byfungal pathogens often causing damage on rice crop. Thisstudy was aimed to characterize 10 endohytic bacterial isolatesin suppression of rice pathogenic fungi. Characterization by invitro test showed several endophytic isolates effective againstfungal pathogen Rhizoctonia solani (Rs) and Pyriculariaoryzae (Po). The bacterial culture filtrates could inhibit radialgrowth of fungal colonies with the Rs ranged percentageinhibition of 32.9-99.4%, whilst inhibition against Po wereranged from 3-98.2%, respectively. Based on chitinase assay,it was indicated that gram negative bacteria of E 76 isolateproduced clear zone and highest chitinolytic index. Theanalysis to the base sequence (total 1,322 bp) using 16s rRNAgene sequencing revealed that E76 isolates had 99% similaritywith Burkholderia sp

Control of Anthracnose Disease (Colletotrichum Gloeosporioides) Using Nano Chitosan Hydrolyzed by Chitinase Derived From Burkholderia Cepacia Isolate E76

Anthracnose (Colletotrichum gloeosporioides) is one of the important diseases of fruit crops that need to be controlled. This study was aimed to obtain the best formula of hydrolyzed nano chitosan and its potensial in controlling anthracnose. The hydrolyzed chitosan was prepared using chitinase enzyme extracted from Burkholderia cepacia isolate E76. Chitosan nanoparticles were synthesized using ionic gelation method by reacting hydrolyzed chitosan (0.2%) with Sodium tripolyphosphate (STPP) (0.1%) as cross-linking agent using 30–60 minutes stirring condition. The bioactivity of the nano chitosan formula was tested to C. gloeosporioides under in vitro and in vivo assays. The specific enzymatic activity of the purified chitinase was higher (0.19 U/mg) than that of crude enzyme (supernatant) with the purity increased by 3.8 times. Of the four formula tested, Formula A (hydrolyzed chitosan to STPP volume ratio of 5 : 1 with 60 minutes stirring condition) was found good in terms of physical characteristic of the particle. The formula nano chitosan particle had the spherical-like shape with an average particle size of 126.2+3.8 nm, polydispersity index (PI) of 0.4+0.02, and zeta potential (ZP) value of 27.8+0.2 mV. Nano chitosan had an inhibitory activity to C. gloeosporioides in vitro up to 85.7%. Moreover, it could inhibit 61.2% of C. gloeosporioides spores germination. It was shown that nano chitosan was also effective to reduce anthracnose disease severity in vivo when applied as a preventive measure on Chili and papaya fruits. This study could be used as a reference for further fruit coating application using nano chitosan as a promising postharvest biocontrol agent to C. gloeosporioides

Keragaman Genetik Rizobakteri Penghasil Asam Indol Asetat Berdasarkan 16S RRNA dan Amplified Ribosomal DNA Restriction Analysis

Asam indol asetat (AIA) dapat dihasilkan oleh bakteri rizosfer/rizobakteri pemacu pertumbuhan tanaman (PPT). Keragaman genetik isolat bakteri PPT indigenous Indonesia perlu diinvestigasi untuk mencari sumber potensial agen PPT dengan informasi kekerabatan intra dan interspesies yang jelas. Karena itu penelitian ini bertujuan mengetahui keragaman genetik rizobakteri penghasil AIA indigenous Indonesia dengan gen 16S rRNA, dilengkapi dengan ARDRA. Koleksi isolat bakteri BB Biogen diidentifikasi kandungan AIA-nya, morfologi secara makroskopis dan sekuensing pada sekuen 16S rRNA dan ARDRA. Total empat belas isolat rizobakteri memiliki kandungan AIA dalam kisaran 5,24-37,69 µg/ml dan tertinggi pada SM1. Karakteristik morfologi koloni rizobakteri mendukung variasi strain bakteri penghasil AIA. Delapan isolat terpilih diidentifikasi sebagai spesies Bacillus dengan homologi 96-99%. Lima isolat (SM1, JP4, KP3, MB2, dan CP3) diidentifikasikan sebagai B. subtilis, SC2 sebagai B. amyloliquefaciens, BL2 dekat dengan B. velezensis, dan JP3 memiliki homologi tinggi dengan Brevundimonas olei. Delapan isolat rizobakteri tersebut berkerabat dekat dengan strain bakteri referensi yang memiliki kesamaan spesies. Analisis ARDRA-RsaI menghasilkan lima filotipe dengan keunikan pola sidik jari. Isolat CP3, MB 2, dan KP 3 berada dalam satu filotipe. Kedekatan isolat dalam Bacillus sp. digambarkan oleh filotipe 5 (B. subtilis SM1 dan B. velezensis BL2) yang diduga jauh dari B. amyloliquefaciens SC2 (filotipe 4) dan JP 3 pada genus Brevundimonas (filotipe 3). Keragaman genetik isolat rizobakteri penghasil AIA terhitung rendah berdasarkan 16S-rRNA dan ARDRA-RsaI