Kattaleeya Yurayard Polson Mahakhan Kanit Vichitphan Sukanda Vichitphan Duangdao Khamprasert and Jutaporn Swangkeaw
Agricultural cellulosic material is importance for bio-energy production because it is cheap, abundant and virtually inexhaustible source of renewable bioenergy. Cellulolytic enzymes are major group of enzyme that is capable degrading cellulose to glucose. This study aimed on screening of fungi producing carboxymethyl cellulase which was isolated from 48 samples of soil, wood and leaf decay in Chaiyaphum province, the northeastern part of Thailand. Only 25 fungal isolates exhibited carboxymethyl cellulase activity on plate screening assay. The selected 5 fungal isolates (HS1-3, HS1-5, HS1-7, HS1-12, HS2-5) which exhibited high carboxymethyl cellulase on the agar plate were grown and their abilities of enzyme production were determined. The 5 fungal isolates were cultured in mineral salt agar medium at pH 5.0 containing 1.0% carboxymethyl cellulose and incubated at 150 rpm, 30°C for 7 days. The results showed that fungal isolate HS1-3 exhibited the highest enzyme activity (150 U/mL). The identification of fungal isolate HS1-3 was carried out by the internal transcribed spacer region (ITS) DNA sequencing and compared with BLASTN Homology Search. The results indicated that the DNA sequence of fungal isolate HS1-3 was 100 percent (1046/1046 nucleotides) identical with Penicillium oxalicum, GenBank accession number HQ843504.1.
ปรีดา จันทวงษ์ บวร อิศรางกูร ณ อยุธยา และ โยธิน อึ่งกูล
This paper reports experimental comparative study between a Roof Autoclaved Aerated Concrete Solar Chimney (RCSC) and Simple Roof Concrete (SRC). The RCSC design used CPAC Monier concrete in dark red colour and transparent tiles on the outer side were 0.015 m thickness, 0.01 m air gap, and Autoclaved Aerated concrete panes was 0.07 m. and painted black colour to induce the highest natural ventilation rate. Its dimensions were 0.70 m2 of area, and size of openings was 0.10 x 0.4 m2 and 0.15 x 0.60 m2, openings were located at the bottom (room side) and at the top (ambient side). The RCSC was installed at the south façade of two small houses with the same dimension, small houses has a volume of 4.05 m3. Then, the performance comparison between RCSC and SRC for reducing thermal heat gain the ceiling, using another small house model, was studied. The experimental results revealed that indoor temperature of RCSC room was lower than that of the SRC room. This ventilation reduced heat gain admitted through the south roof considerably. The RCSC is expected to promote solar energy use, save cooling energy, and protect environment.
Pailin Jitchum Alonggot Intarachart and Ladda Wongrat
The plankton community was studied twice a week from September 2006 to August 2007, in a green mussel raft-cultured area, Si Racha Bay, in the Gulf of Thailand. Phytoplankton was collected by filtering with a 20 µm plankton net and zooplankton was collected by vertical hauling with a plankton net of 330 µm mesh size. Several hydrographical conditions were measured in situbut nutrient analyses of water samples were carried out in the laboratory. Fifty seven genera of phytoplankton and 34 groups of zooplankton were recorded. The mean abundance of phytoplankton was 38,777 ± 27,453 units l-1 while that of zooplankton was 3,368 ± 1,183 ind. m-3. The dominant group of phytoplankton was diatoms; while copepods, cirripede nauplii, Lucifer sp., and Sagitta spp. were the major contributors to zooplankton abundance. Noticeable variation in composition of phytoplankton was demonstrated by an algal bloom of dinoflagellates (Ceratium furca (Ehrenberg) Claparède & Lachmann) in July 2007. The plankton community showed no significant differences in abundance between months in the annual cycle but the high value was during the Southwest monsoon. Moreover, the average value of primary production (3.85 ± 2.79 mg m-3) during the Southwest monsoon was higher than that of the Northeast monsoon season (1.11 ± 0.36 mg m-3). Composition variation was also influenced by water temperature, salinity, ammonia and dissolved oxygen. Hydrographical conditions and nutrients showed temporal fluctuations. In this regard, the maximum values of nutrients and dissolved oxygen agreed with Thai standard levels of seawater suitable for an aquaculture area.
A Phytoplankton community survey was carried out in the seagrass beds of Ao Lo Pa Lai and Ao Lo Po Yai, Ko Yao Yai, Phangnga Province. Sampling was conducted in January and July 2005. Water samples were filtered through a nylon net with mesh size 20 micrometers. A total of 4 classes with 57 genera were identified as Cyanophyceae (4 genera), Bacillariophyceae (39 genera), Dinophyceae (13 genera) and Dictyochophyceae (1 genera). The dominant genera consisted of Cylindrotheca, Nitzschia, Pleurosigma, Pseudo-nitzschia, Paralia, Chaetoceros and Thalassiosira. Diatom was the dominant group from both study areas. Cylindrotheca and Nitzschia were found in high abundance at Ao Lopoyai. Species diversity index, similarity index and richness index ranged between 0.89 – 1.39, 0.56 – 0.91 and 2.51 – 4.94, respectively. The relationships between environ-mental factors and phytoplankton abundance demonstrated that the phytoplankton abundance negatively correlated with pH and positively correlated with chlorophyll a concentrations.
ขจรเกียรติ์ ศรีนวลสม บัญญัติ มนเทียรอาสน และ จงกล พรมยะ
The objective of this research was to investigate the efficiency of 3 culture systems for the Mekong giant catfish (Pangasianodon gigas) (non natural food establishment, natural food estab-lishment and mix system) on the species diversity, biomass of phytoplankton and water quality. The experiment was divided into 3 treatments; non natural food establishment (T1), natural food establishment (T2) and mix system (T3). The result showed that, the diversity of phytoplankton present in the pond belonged to 6 divisions, and 43 species, such as Cyanophyta, Chlorophyta, Chrysophyta, Euglenophyta, Pyrrophyta and Cryptophyta. Most of the species belonged to the Division Chlorophyta. The biomass of phytoplankton was found to be highest in treatment 2; natural food establishment. The dominant species of phytoplankton were Scenedesmus sp. and Euglena sp. There were significant differences (P<=0.05) among the average water qualities. The information obtained can be used as a baseline for management and development in Pla Buk culture systems in the future.
ชัชรี แก้วสุรลิขิต และ ธีระพงศ์ ด้วงดี
The species diversity of marine algae at Hingrood Reef and Koh Talu Islands was observed by SCUBA diving down 15 meters in July 2007. Twenty five species of 22 genera and 17 families were reported, of which, 7 species were green, 6 species were brown and 12 species were red. The dominant species were Lobophora variegata, Turbinaria conoides, T. decurrens, Hypnea spinella, Gelidiopsis variabilis, Peyssonnelia boergesenii, Pterocladiella caloglossoides and nongeniculated coralline red algae. The highest diversity, 13 species, was found in Koh Talu while 8 species were found in Hin-Grood Reef.
เพ็ญไพลิน อุดมรัตน และ อัจฉราภรณ์ เปี่ยมสมบูรณ์
This study on morphological variations of Dinophysis caudata (Saville-Kent) was carried out in the coastal area of Samut Sakhon Province. Sampling stations were located on the western part of Tha Chin estuary in Khasa-khao village where there were frequent records of the red tide phenomena. Physico-chemical parameters were measured with water and phytoplankton samples being collected monthly from June 2007 to May 2008. D. caudata was isolated and photographed under a compound microscope for the measurement of cell dimensions with an Image Pro-plus program. The presence of 56 morphotypes of D. caudata were recorded with the cell width varying from 10.08 to 35.60 mm (average 21.65 ± 4.27 mm) and cell length in the range of 29.54 – 76.56 mm (average 46.03 ± 8.45 mm). These characteristics can be divided into 4 groups based on frequency of occurrence in terms of cell length and width. The most dominant cell type was the small-sized cells with cell widths and lengths in the range of 18 - 25 mm and 38 - 52 mm, respectively. The occurrence in terms of these small cells tended to follow the variation in pH and nitrate-nitrogen concentrations in seawater, while the abundance of large-sized cells (> 30 mm width and > 64 mm length) showed a significant relationship with DIN:DIP ratio in the water column.
สุเมธ เชิงสะอาด และ อนงค์ จีรภัทร
Morphological variation of the brown alga Sargassum polycystum C. Agardh was investigated from specimens collected from the coast of Samaesan in Chon Buri province. The characteristics of thallus i.e. thallus length, holdfast diameter, blade and vesicle size were measured. Shape and reproductive characters were also examined and drawn with a Camera Lucida. Plants of S. polycys-tum were yellowish brown in color, holdfasts discoid had a short cylindrical stipe, main axes were terete being obvious rough or spiny. The blade of the secondary order branch was divided into 3 types: 1) large and lanceolate shaped, 2) large and broader than type 1 and 3, and 3) smaller and lanceolate shaped. These three types were significantly different (P < 0.05). Of those three char-acters, leaf margin serrate, midrib running to near the apex of the blade. Cryptostomata scattered on the surface of the blade. Vesicles varied within a thallus which were divided into 4 characters i.e. 1) ovate shaped 2) ovate to circular shaped with 2 spines on surface 3) ovate with 5-6 spines on surface and 4) ovate with winged-margin and a few cryptostomata. Single or multiple vesicles on the primary and secondary branches; male and female receptacles separated. Male receptacles were long and cylindrical, up to 8 mm long in singularly or in pairs. Female receptacles were cy-lindrical at lower portion, but slightly compressed at the upper portion, up to 4 mm long. Stolon arising from primary branch differentiated into a new thallus. This study found the vesicles type 4 with winged-margin showing different characters from previous reports of this species in this area.
This work investigated the cultivation of Skeletonema costatum in a 3L airlift photobioreactor which was operated at superficial air velocity of 1.5 cm s-1, light intensity of 33.78 mmol photon m-2s-1 with an initial cell density of 0.4x106 cell mL-1. The cultivation in a standard Guillard F/2 medium provided the final culture with a maximum cell density of 1.96x106 cell mL-1 at a specific growth rate of 0.032 h-1. Experimental findings reveal that a 4 fold increase in silica concentration in the standard Guillard F/2 medium could significantly increase the cell growth with a final cell density of 4.6x106 cell mL-1 at a specific growth rate of 0.046 h-1.
จักรพงษ์ ศรีพนมยม และ ศศิกานต์ กาญจนสมบูรณ์
Culturing of the diatom, Thalassiosira sp. was conducted in the laboratory with an average of 105 cells/ml at 28 ± 1 ºC, pH 7.5 ± 0.2 and light intense of 4,000 lux. Four types of media were AGP (commercial grade), Guillard (F/2), Conway and Conway modified (MF) were compared. The growth was recorded every 6 hours until to the maximum cell density was reached. The continuing culture was finished when the cell density decreased 4 times within 24 hr. The results showed the maximum cell density of AGP, F/2, Conway and MF medium were 6.47 ± 0.198, 6.18 ± 0.168, 5.89± 0.198 and 9.08 ± 0.307 × 105 cells/ml, respectively. MF medium showed the highest time interval followed by Conway, F/2 and AGP with 156, 144, 102 and 96 hr., respectively. The statistical analy-sis showed significant differences in maximum density between MF medium and the other media. The cell size decreased in series form AGP, F/2, Conway and MF medium. The average cell widths were 7.74 ± 1.07, 7.16 ± 1.21, 6.47 ± 1.01 and 5.92 ± 0.93 micrometers, respectively. The average cell lengths were 18.17 ± 0.51, 16.41 ± 1.03, 15.26 ± 1.12 and 15.07 ± 1.04 micrometers, respectively. Abnormal cells and contamination were not recorded. pH ranged from 7.76-8.37,nitrate, nitrite, ammonia, orthophosphate and total phosphorus varied form 0.94-2.20, 0.005-0.086, 0.010-1.577, 0.013-0.165 and 0.078-0.528 mg/l, respectively.
กิตติพล กสิภาร วัชระ เวียงแก้ว ศิริวรรณ ศรีสรฉัตร และ ชนาธิป สามารถ
The objective of this study was to investigate the optimum conditions for cultivation of Chlorella vulgaris in a 1-L bioreactor using statistical experimental design. The results were success-fully determined by response surface methodology of Box-Behnken and will be used to design the pilot plant bioreactor. Experimental factors effecting the optimum conditions were the cultivation temperature of 25-40 °C, the pH of 6-8 and the volumetric ratio of carbon dioxide of 1.6–7.7%. It was found that the optimum conditions for cultivation were 29.6°C, pH = 7.26 and the volumetric flow rate of carbon dioxide of 16.18 ml/min or carbon dioxide volumetric ratio of 2.63% giving a specific growth rate of 0.389 day-1.