The aim of this paper is to investigate the characteristics of thermoplastic sugar palm starch/agar (TPSA) blend containing Eucheuma cottonii seaweed waste as biofiller. The composites were prepared by melt-mixing and hot pressing at 140°C for 10min. The TPSA/seaweed composites were characterized for their mechanical, thermal and biodegradation properties. Incorporation of seaweed from 0 to 40wt.% has significantly improved the tensile, flexural, and impact properties of the TPSA/seaweed composites. Scanning electron micrograph of the tensile fracture showed homogeneous surface with formation of cleavage plane. It is also evident from TGA results that thermal stability of the composites were enhanced with addition of seaweed. After soil burial for 2 and 4 weeks, the biodegradation of the composites was enhanced with addition of seaweed. Overall, the incorporation of seaweed into TPSA enhances the properties of TPSA for short-life product application such as tray, plate, etc.
Rice brown spot (BS) exerts devastating agronomic effects on grain quality and overall productivity. In Peninsular Malaysia, BS disease incidence is fairly prevalent and little is known about the diversity of BS pathogens in the local granaries. Fifteen isolates from BS symptomatic rice plants were identified at five different rice granaries across Peninsular Malaysia. Based on the morphological and molecular analyses, two isolates were confirmed as Bipolaris oryzae while the rest were identified as Exserohilum rostratum. Phylogenetic tree analysis revealed that BS incidence in rice granaries in Peninsular Malaysia is caused by a pair of closely related fungal pathogens, E. rostratum and B. oryzae, with the former being more predominant. Cultural characterization of E. rostratum isolate KT831962 showed the best growth and sporulation activity on corn meal agar plates incubated in complete darkness. The effects of calcium silicate (CaSiO3) and rice husk ash (RHA) soil amendment against MR219 and MR253 rice varieties were evaluated during rice-E. rostratum interaction. Results showed that soil amelioration using CaSiO3 and RHA singly and in combination with manganese (Mn) significantly reduced rice BS disease severity. The BS disease index was reduced significantly to less than 31.6% in the silicon-treated rice plants relative to the control plants at 41.2%. Likewise, the grain yield at the harvest stage showed significantly higher yield in the Si-treated rice plants in comparison to the control, non-Si treated rice plants. The findings highlight the potential of RHA agro-waste as Si fertilizer in a sustainable rice production system.
Rawatan ortodontik boleh menjejaskan keseimbangan mikrobiota oral yang memainkan peranan utama dalam etiologi penyakit periodontium. Kajian klinikal prospektif ini bertujuan untuk menilai kesihatan periodontal dan profil mikrobiologi pesakit periodontal yang sihat (Kumpulan 1) dan yang telah stabil (Kumpulan 2) selama tiga bulan pertama semasa rawatan ortodontik. Aplian ortodontik atas dan bawah tetap dipasang. Kesihatan periodontium dinilai menggunakan skor plak (PS), pendarahan pada probing (BOP) dan kedalaman poket (PD). 29 tapak telah diambil untuk persampelan plak subgingival. Sampel plak diinokulasikan pada agar Trypticase Soya Darah (TSBA) dan agar Trypticase Soya Bacitracin Vancomycin (TSBV) untuk penilaian aerob, anaerob, bakteria berpigmen hitam (BPH) dan Aggregatibacter actinomycetemcomitans. Semua ukuran diambil sebelum pendakap gigi dipasang (T0), 1 minggu (T1), 1 bulan (T2) dan 3 bulan selepas dipasang pendakap gigi (T3). Secara umumnya, kesihatan periodontium dalam kedua-dua kumpulan hampir sama. Selepas 1 minggu, bilangan aerob adalah lebih tinggi dalam Kumpulan 1 (88%) manakala anaerob adalah lebih tinggi dalam Kumpulan 2 (45%). A. actinomycetemcomitans lebih tinggi dalam Kumpulan 1 pada T0 dan T1 tetapi jauh lebih tinggi dalam Kumpulan 2 di T3. BPH adalah minimal pada setiap masa dengan tiada perbezaan signifikan. Oleh itu, semasa 3 bulan pertama rawatan ortodontik dijalankan, terdapat perubahan ketara dalam bilangan aerob-anaerob pada kedua-dua pesakit periodontal yang sihat dan stabil. Bakteria patogenik akan meningkat semasa rawatan awal ortodontik.
Mid-exponential phase Saccharomyces rouxii YSa40 cells subsequently stressed at low aw/pH in the 0.64 aw/pH 3.5 glycerol/CPB system became injured. Such injury was detected by the loss of ability of the
stressed population to form colonies on secondary-stress plating medium (glycerol/BM agar at 0.94 aw
/pH 3.5 (lactic acid)) while colony forming ability on secondary non-stress plating medium (sugars/BM agar at 0.94 aw/pH 3.5 (lactic) was unaffected. The injury was shown to be due to sensitivity to glycerol/lactic acid. Results of the present study will be useful for achieving complete decontamination of ‘Intermediate Moisture Foods’ against xerotolerant molds and yeast.
Acanthamoeba is a free living protozoa that can cause keratitis and granulomatous amoebic encephalitis. Physiological characteristics of this amoeba are found to have a medical importance in which it can be related to the pathogenicity potential of the organism. This study was carried out to investigate the physiological characteristics of survivability during axenization. Six Acanthamoeba strains from three clinical isolates (HSB 1, HKL 48 and HKL 95) and three environmental isolates (PHS 2, PHS 11 and PHS 15) were used in this study. Axenization test was done by treating cysts with hydrochloric acid (3%) and Page saline containing Gentamicin (100 μg/ml). Cysts were then cultured into PYG enrich media, incubated at 30oC and the presence and proliferation of trophozoites of Acanthamoeba were observed. This study showed that PHS 15, HSB 1, HKL 48 and HKL 95 could be axenized but they have poor proliferation rate in PYG enrich media. The result showed that the difference between both clinical and environmental isolates was observed in two strains; PHS 2 and PHS 11. This indicates that there is a possibility that the physiological traits of strains from both isolates are the same and strains from the environment are able to show the pathogenic potential and capable of causing infection to human.
Keywords: Axenization, Survivability, Acanthamoeba, Clinical and environmental strains
Bakteria endofit adalah berpotensi untuk menghasilkan antibiotik dan metabolit sekunder yang lain. Penghasilan metabolit sekunder dapat ditingkatkan melalui pengoptimuman kandungan nutrien seperti sumber nitrogen. Dalam kajian ini kandungan sumber nitrogen iaitu ammonium sulfat, ammonium dihidrogen fosfat, kalium nitrat dan natrum nitrat telah diubahsuai di dalam kaldu International Streptomyces Project 4 (ISP4) untuk pertumbuhan Streptomyces SUK 02. Pengekstrakan dilakukan dengan menggunakan etil asetat dan aktiviti antifungus ditentukan dengan menggunakan teknik serapan agar. Fungus ujian yang digunakan adalah Aspergillus fumigatus dan Fusarium solani. Hasil kajian menunjukkan peratusan berat (w/v) ekstrak kasar maksima didapati daripada kaldu yang mengandungi natrium nitrat (3.30%), diikuti oleh ammonium dihidrogen fosfat (2.24%), ammonium sulfat (1.46%) dan kalium nitrat (1.20%). Aktiviti antifungus dikesan daripada ekstrak bersumberkan nitrogen ammonium sulfat.Peratus perencatan ekstrak tersebut terhadap Aspergillus fumigatus dan Fusarium solani adalah 33.0-35.0% dan 17.4-30.0%, masing-masing. Manakala nilai MIC terhadap Aspergillus fumigatus adalah 1.5 mg/ml. Sebagai kesimpulan, natrium nitrat merupakan sumber nitrogen yang sesuai bagi partumbuhan optimum Streptomyces SUK 02 manakala kehadiran ammonium sulfat boleh meningkatkan aktiviti antifungus.
Kajian ini untuk menunjukkan bahawa penentuan tanah air umat Melayu perlu dilihat dalam perspektif pendekatan atau teori yang baru, yakni teori 'The New Malay Homeland'. Ahli Linguistik sejarah pada abad ke-20 dan pada abad ini, iaitu pada abad ke-21 banyak telah melakukan kajian untuk membuktikan bahawa sebenarnya umat Melayu bukan bermigrasi daripada Yunan, sebaliknya daripada Taiwan dan kemudiannya menjadikan Borneo sebagai tanah air kedua umat Melayu. Untuk menjitukan lagi teori ini, maka kajian rekonstruksi dan klasifikasi bahasa Iban di Sarawak dilakukan agar maklumat-maklumat fosil linguistik yang wujud dalam bahasa Iban pada peringkat purbanya dapat membuktikan dan memperkukuhkan hujah bahawa teori di atas adalah benar. Dua kaedah kajian diaplikasi dalam penelitian ini, iaitu kaedah kepustakaan dan kaedah lapangan. Kaedah kajian kepustakaan lebih melihat kepada aspek pembacaan untuk mendapatkan maklumat berkaitan bidang kajian. Kajian-kajian awal ke atas bahasa Iban sejak abad ke-18 sehinga abad ke-21 telah diselidiki. Maklumat berkaitan bidang ilmu linguistik bandingan juga telah dibaca secara seksama. Berkaitan kaedah kajian lapangan, metode semak dan metode cakap dengan pengaplikasian teknik-teknik khas telah dilakukan. Berdasarkan lokasi kajian, tujuh varian bahasa Iban telah diteliti, yakni varian Iban Sri Aman (SA), Betong (BTG), Sarikei (SKEI), Sibu (SBU), Kapit (KPT), Bintulu (BTL) dan Limbang (LMBG) . Hasil penelitian menunjukkan bahawa bahasa Iban Purba Sarawak (IPS) memiliki enam fonem vokal *a, *a, *i, *u, *e, *o; tiga diftong *-uy, *-ay, *-aw dan sembilan belas konsonan, iaitu *p, *b, *t, *d, *k, *g, */, *s, *h, *1, *r, *m, *n, *0, *N, *dZ, *tS, *w, dan *y. Beberapa inovasi fonologi juga diperoleh apabila perbandingan dilakukan antara IPS dengan Bahasa Melayik Purba (BMP), iaitu i) BMP *h > IPS */; ii) BMP *-d > IPS *zero, iii) BMP *-g > IPS *zero, iv), dan BMP *r, *1 > IPS *r. Pada tahap morfologi wujud inovasi dan retensi antara IPS dan BMP, iaitu BMP *ni/di > IPS *ba/ dan morfem BMP *{une (N)}, *{be(R)} dan *ite(R)1 diretensi sepenuhnya dalam IPS. Berdasarkan dapatan daripada kajian ini membuktikan bahawa terdapat ikatan rapat antara BMP dengan IPS dapatan ini juga membuktikan bahawa Borneo adalah tanah air kedua umat Melayu setelah umat ini bermigrasi keluar daripada Taiwan.
Kajian ini dijalankan untuk memencilkan Acanthamoeba spp. daripada pelbagai persekitaran akuatik di Semenanjung Malaysia. Sebanyak 160 sampel diambil dengan 140 sampel menggunakan kaedah swab manakala 20 sampel lagi menggunakan kaedah pensampelan air dengan botol Schott 500 ml yang steril. Sampel swab diambil daripada kepala paip air (50), sinki (50), serta kolam renang (40) manakala sampel air diambil dari laut. Sampel swab diinokulasi secara terus ke atas agar tanpa nutrien (NNA) yang dilapisi dengan Escherichia coli matian haba secara aseptik. Sampel air dituras menggunakan membran turas bersaiz liang 0.45 µm sebelum membran turas itu dipindahkan secara aseptik ke atas piring NNA yang dilapisi dengan E. coli matian haba. Semua piring dieram pada suhu 30°C dan diperiksa setiap hari untuk kehadiran Acanthamoeba spp. sehingga hari ke-14 sebelum disahkan negatif. Secara keseluruhannya, terdapat 20% sampel yang positif untuk kehadiran Acanthamoeba. Acanthamoeba spp. paling banyak dipencilkan daripada sampel air laut dengan peratusan sebanyak 40% manakala paling sedikit dipencilkan daripada swab paip air dengan peratusan sebanyak 4% sahaja. Pencilan positif Acanthamoeba spp. daripada sinki dan kolam renang masing-masing adalah 20% dan 30%. Ketiga-tiga kumpulan genus Acanthamoeba dalam bentuk sista dapat ditemui dalam sampel yang diambil.
Y. enterocolitica and Y. pseudotuberculosis are important food borne pathogens. However, the presence of competitive microbiota makes the isolation of Y. enterocolitica and Y. pseudotuberculosis from naturally contaminated foods difficult. We attempted to evaluate the performance of a modified Cefsulodin-Irgasan-Novobiocin (CIN) agar in the differentiation of Y. enterocolitica from non-Yersinia species, particularly the natural intestinal microbiota. The modified CIN enabled the growth of Y. enterocolitica colonies with the same efficiency as CIN and Luria-Bertani agar. The detection limits of the modified CIN for Y. enterocolitica in culture medium (10 cfu/ml) and in artificially contaminated pork (10(4) cfu/ml) were also comparable to those of CIN. However, the modified CIN provided a better discrimination of Yersinia colonies from other bacteria exhibiting Yersinia-like colonies on CIN (H2S-producing Citrobacter freundii, C. braakii, Enterobacter cloacae, Aeromonas hydrophila, Providencia rettgeri, and Morganella morganii). The modified CIN exhibited a higher recovery rate of Y. enterocolitica from artificially prepared bacterial cultures and naturally contaminated samples compared with CIN. Our results thus demonstrated that the use of modified CIN may be a valuable means to increase the recovery rate of food borne Yersinia from natural samples, which are usually contaminated by multiple types of bacteria.
Restriction endonuclease analyses (REAs) constitute the only inexpensive molecular approach capable of typing and characterizing human adenovirus (HAdV) strains based on the entire genome. However, the application of this method is limited by the need for time-consuming and labor-intensive procedures. We herein developed a simple and cost-effective REA for assessing HAdV. The method consists of (1) simple and cost-effective DNA extraction, (2) fast restriction endonuclease (RE) digestion, and (3) speedy mini agarose gel electrophoresis. In this study, DNA was isolated according to the kit-based method and 21.0 to 28.0 μg of viral DNA was extracted from prototypes (HAdV-1, HAdV-3, HAdV-4, and HAdV-37) in each flask. The amount of DNA ranged from 11.4 to 57.0 μg among the HAdV-3 (n=73) isolates. The obtained viral DNA was found to be applicable to more than 10 types of REAs. Fast-cut restriction endonucleases (REs) were able to digest the DNA within 15 minutes, and restriction fragments were easily separated via horizontal mini agarose gel electrophoresis. The whole procedure for 10 samples can be completed within approximately six hours (the conventional method requires at least two days). These results show that our REA is potentially applicable in many laboratories in which HAdVs are isolated.
Matched MeSH terms: Electrophoresis, Agar Gel/economics; Electrophoresis, Agar Gel/methods
Miniaturisation of microchip capillary electrophoresis (MCE) is becoming an increasingly important research topic, particularly in areas related to micro total analysis systems or lab on a chip. One of the important features associated with the miniaturised MCE system is the portable power supply unit. In this work, a very low electric field MCE utilising an amperometric detection scheme was designed for use in DNA separation. The device was fabricated from a glass/polydimethylsiloxane hybrid engraved microchannel with platinum electrodes sputtered onto a glass substrate. Measurement was based on a three-electrode arrangement, and separation was achieved using a very low electric field of 12 V/cm and sample volume of 1.5 µl. The device was tested using two commercial DNA markers of different base pair sizes. The results are in agreement with conventional electrophoresis, but with improved resolution. The sensitivity consistently higher than 100 nA, and the separation time approximately 45 min, making this microchip an ideal tool for DNA analysis.
Matched MeSH terms: Electrophoresis, Agar Gel/instrumentation; Electrophoresis, Agar Gel/methods
Recently, there has been considerable interest in the use of miniaturized sample preparation techniques before the chromatographic monitoring of the analytes in unknown complex compositions. The use of biopolymer-based sorbents in solid-phase microextraction techniques has achieved a good reputation. A great variety of polysaccharides can be extracted from marine plants or microorganisms. Seaweeds are the major sources of polysaccharides such as alginate, agar, agarose, as well as carrageenans. Agarose and alginate (green biopolymers) have been manipulated for different microextraction approaches. The present review is focused on the classification of biopolymer and their applications in multidisciplinary research. Besides, efforts have been made to discuss the state-of-the-art of the new microextraction techniques that utilize commercial biopolymer interfaces such as agarose in liquid-phase microextraction and solid-phase microextraction.
The aim of this work is to study the behavior of biodegradable sugar palm starch (SPS) based thermoplastic containing agar in the range of 10-40wt%. The thermoplastics were melt-mixed and then hot pressed at 140°C for 10min. SEM investigation showed good miscibility between SPS and agar. FT-IR analysis confirmed that SPS and agar were compatible and inter-molecular hydrogen bonds existed between them. Incorporation of agar increased the thermoplastic starch tensile properties (Young's modulus and tensile strength). The thermal stability and moisture uptake increased with increasing agar content. The present work shows that starch-based thermoplastics with 30wt% agar content have the highest tensile strength. Higher content of agar (40wt%) resulted to more rough cleavage fracture and slight decrease in the tensile strength. In conclusion, the addition of agar improved the thermal and tensile properties of thermoplastic SPS which widened the potential application of this eco-friendly material. The most promising applications for this eco-friendly material are short-life products such as packaging, container, tray, etc.
Pulp and paper mill sludge (PPMS) was found to be poorly colonised with thermophilic microorganisms. However,
evidence to support the need for inoculation to facilitate PPMS composting has only been demonstrated in one instance.
In this study, we aimed to: screen and identify PPMS digesting thermophilic bacterial strains; investigate effects of the
mixture of selected thermophilic bacterial strains on PPMS digestion; and utilize this mixture as start inoculum in PPMS
composting and assess the quality of compost product. The results showed that eleven thermophilic bacterial strains were
isolated from Bai Bang PPMS by the enrichment culture method. Among these, three strains which reflected high growth
rates on the plates of Minimal Media Agar supplemented with Bai Bang PPMS and showed hydrolytic and ligninolytic
activities on the agar plates containing appropriate inductive substrates were selected. Based on the morphological,
biochemical characteristics and 16S rRNA gene sequencing, they were identified as Bacillus subtilis. The inoculation
with the mixture of selected strains enhanced remarkably Bai Bang PPMS digestion. The dry weight decrease, volatile
suspended solids removal, dehydrogenase and protease activities in the inoculated sludge were 2.1-, 1.5-, 1.3- and 1.2-
fold higher, respectively, compared to the non-inoculated sludge. The assessment of compost quality based on stability
using the alkaline trap method and maturity using the germination and root elongation test showed that the inoculated
compost was stable and mature while the non-inoculated compost was unstable and immature. These thermophilic
bacterial strains therefore have great potential for Bai Bang PPMS composting.
Introduction: This study reported the concentration of bacterial and fungal bioaerosol at an animal house and hospi- tal laboratories with the aim to compare the concentration levels at library and administrative offices. The bioaerosol levels between mid-shift (afternoon) were also compared to the concentration measured during pre-shift (morning). Methods: The NIOSH 0800 method utilising microbiological air sampler collecting airborne bacterial and fungal samples via impaction technique on Nutrient agar (NA) and Sabouraud Dextrouse agar (SDA) as culture medium, respectively. Sampling was done twice daily; before (pre-shift) and during working (mid-shift) hour. Results: The highest bacteria and fungi concentration was recorded at the animal house with median concentration of 2477 CFU/ m3 (IQR=121-2477) and 791 CFU/m3 (IQR = 379-2081), respectively. Higher-risked workplaces such as animal house and hospital laboratories have significantly higher bioaerosol concentrations compared to control workplaces such as library and administrative offices (p
A type strain of Lactarius deliciosus was obtained from the CBS-KNAW culture collection. The mycelium was cultured using potato dextrose agar, and the extracted genomic DNA was subjected to PacBio genome sequencing. Upon assembly and annotation, the genome size was estimated to be 54 Mbp, with 12,753 genes.
Kajian ini dilakukan untuk menentukan hubungan antara motivasi membaca, persekitaran membaca di rumah dan sikap membaca dalam kalangan pelajar Universiti Putra Malaysia. Seramai 214 pelajar UPM yang dipilih melalui kaedah persampelan pelbagai peringkat terlibat dalam kajian ini. Satu set borang soal selidik yang diedar kepada responden mengandungi tiga instrumen iaitu Survey of Adolescent Reading Attitudes, Motivations for Reading Questionnaire (MRQ) dan Students’s Reading Environments at Home: Exposure and Support. Hasil kajian menunjukkan sikap membaca bahan bacaan digital dan bercetak pelajar UPM berada pada tahap tinggi. Selain itu, kajian mendapati motivasi membaca intrinsik dan ekstrinsik serta persekitaran membaca di rumah pelajar UPM berada pada tahap sederhana. Keputusan menunjukkan terdapat hubungan positif secara signifikan antara motivasi membaca intrinsik, motivasi ekstrinsik dan persekitaran membaca di rumah dengan sikap membaca bahan bacaan digital dan bercetak. Kesimpulannya, motivasi membaca dan persekitaran membaca di rumah mempunyai hubungan signifikan dengan sikap membaca dalam kalangan pelajar UPM. Untuk melahirkan generasi yang mempunyai sikap membaca yang positif, pihak yang bertanggungjawab seperti ibu bapa terutamanya perlu mewujudkan persekitaran membaca yang kondusif di rumah agar dapat memupuk motivasi membaca dan sikap yang positif dalam kalangan anak-anak. Selain itu, pihak univerisiti dan pensyarah juga perlu mengambil langkah yang proaktif dalam mempromosi dan menggalakkan amalan membaca agar ia terus menjadi satu budaya dalam kalangan pelajar di institusi pengajian tinggi.
Black spot disease is a significant worldwide disease on the rose plant. Due to this infection, the leaves become yellow and eventually fall off. The occurrence of this disease has become a major problem, especially in landscape purpose. Therefore, this research was conducted to isolate fungal species from black spot disease in rose and identify using morphological characteristics. Then, all the isolates were tested for pathogenicity to confirm Koch’s postulates. In this study, four fungal isolates have been successfully isolated from black spot disease in rose namely Rhizoctonia sp. (one isolate), Colletotrichum sp. (two isolates) and Penicillium sp. (one isolate). Based on pathogenicity test result using potato dextrose agar (PDA) plug technique, fungus UMTT27R (Penicillium sp.) showed highly pathogenic on rose’s leaves with disease severity (DS) = 88.89% followed by UMTT13R (Colletotrichum sp.) with DS=72.22%, UMTT21R (Colletotrichum sp.) with DS=66.67% and UMTT4R (Rhizoctonia sp.) with DS=61.11%. Correct identification of fungal pathogens is very important to strategize a proper method to control the black spot disease in rose cultivation.
An early step in the Agrobacterium-mediated transformation of Phalaenopsis violacea orchid was investigated to elucidate the plant-bacterium interaction. Directed movement in response to chemical attractants is of crucial importance to Agrobacterium tumefaciens strains. Chemotaxis of A. tumefaciens strains (EHA 101 and 105) towards wounded orchid tissues has been studied by using swarm agar plates. The results obtained indicate a minor role for chemotaxis in determining host specificity and suggest that it could not be responsible for the absence of tumourigenesis in P. violacea orchid under natural conditions. The spectrometric GUS and green fluorescent protein (GFP) assays provided information on the amount of inoculated A. tumefaciens that effectively bound to various orchid tissues. It can be concluded that, at least during the two early steps of interaction, A. tumefaciens appears to be compatible with P. violacea, indicating a potential basis for genetic transformation.
Pencirian enzim ekstraselular protease daripada bakteria Alkalophilic Bacillus lehensis G1 dari Malaysia telah dikaji. Enzim protease yang dirembeskan diuji pada agar susu skim 2%. Keputusan menunjukkan protease ekstraselular mampu mengekalkan aktiviti sehingga suhu 60°C di dalam julat pH yang luas iaitu 3 hingga 11 dengan suhu optimum pada 40°C dan pH optimum pada 7.0. Aktiviti enzim juga diperhatikan akan meningkat dengan penambahan beberapa ion iaitu Mn2+, Fe2+, Cu2+, Mg2+ dan Co2+. Manakala aktiviti protease didapati sedikit direncat dengan kehadiran ion Ca2+, K+ dan Ni2+ dengan baki aktiviti sebanyak 85%, 81% dan 75%. Protease ekstraselular juga didapati serasi dengan beberapa cecair detergen komersial dari Malaysia, yang menunjukkan protease ini boleh dimanfaatkan sebagai pembersih kotoran pada pakaian. Selain itu, potensi kegunaan protease yang dihasilkan oleh B. lehensis G1 ke atas penguraian gelatin dari filem X-ray yang telah digunakan juga telah dilakukan di dalam kajian ini.