A Modified Microtiter Plate Method for Biochemical Characterization of Listeria spp.

1991 ◽  
Vol 54 (2) ◽  
pp. 121-123 ◽  
Author(s):  
GREGORY R. SIRAGUSA ◽  
JERRY W. NIELSEN

A microtiter plate format previously reported for the biochemical characterization of microorganisms was modified by adding agar to all of the different test media instead of using a combination of liquid and solid media. This modification, termed the Modified Microtiter Plate procedure (MMP), offered the same advantages of the original method (labor saving, inexpensive, and custom designed for special needs) as well as having the added advantages of longer term storage prior to use and ease of handling. In this study, 60 bacterial isolates (both Listeria suspects and known Listeria cultures) were biotyped using the MMP protocol and compared to results obtained using the classical tube-based US-FDA recommended protocol as the standard identification method and the BBL-Minitek system.

2020 ◽  
Vol 4 (1) ◽  
pp. 48-54
Author(s):  
Wardha Maulidya Pratiwi ◽  
Rana Yumna Nabila ◽  
Heliza Amalini ◽  
Guntur Trimulyono

The purpose of this study was to obtain cellulolytic bacterial isolates isolated from leaf litter in absorption holes biopori FMIPA Unesa and obtain the most optimal cellulolytic bacterial isolates in cellulose degradation. This research was an observational study and the data were analyzed descriptively. Stages of the study began with bacterial isolation, cellulolytic ability testing, and characterization of cellulolytic bacterial isolates. Bacterial isolation was carried out by the pour plate method, isolation was carried out by the streak plate method, cellulolytic testing was carried out using Carboxy Methyl Cellulose media which was given Congo red 1%. While the isolation characterization was done morphologically, physiologically, and biochemically. The results obtained 15 isolates of cellulolytic bacteria that were tested for their ability to degrade cellulose. Cellulolytic test results showed that 6 isolates, namely BS1, BS7, BS10, BS11, BS14, and BS15 had a cellulolytic index of 0.8, 0.8, 0.8, 0.8, 0.8, 0.8. and 1. Isolates BS15 is the most optimal isolate in cellulose degradation with characteristics of the punctiform colony, yellow pigmentation, entire edge, convex elevation, optical opaque and smooth surface, produces catalase enzymes, is non-motile and can ferment in glucose and starch but cannot ferment lactose and also a Gram-negative


2020 ◽  
Vol 21 (7) ◽  
Author(s):  
Bambang Sulardiono ◽  
NINIEK WIDYORINI ◽  
DJOKO SUPRAPTO ◽  
DIAH AYUNINGRUM ◽  
ARIF RAHMAN

Abstract. Sulardiono B, Widyorini N, Suprapto D, Ayuningrum D, Rahman A. 2020. Evaluation of antibacterial activity and molecular characterization of bacteria from Holothuria atra intestine collected from anthropogenic and non-anthropogenic region in Karimunjawa, Indonesia. Biodiversitas 21: 3149-3155. Evaluation of antibacterial activity and molecular characterization of bacteria from the intestine of Holothuria atra is needed in the anthropogenic region of Menjangan Besar, Karimunjawa. The research aims to evaluate antibacterial activity and molecular characterization of bacteria from intestine of Holothuria atra collected from anthropogenic and non-anthropogenic regions in Karimunjawa, Indonesia. Sea cucumber samples were collected at Menjangan Besar waters as anthropogenic region (code of HM) and Alang-alang waters as non-anthropogenics region (code of HA), Karimunjawa National Park, Indonesia. The H. atra sample collection was using purposive sampling method. Examination of the bacteria from isolation until molecular characterisation was done at the Tropical Marine Biotechnology Laboratory, Uiversitas Diponegoro. The isolation process was conducted using spread plate method, followed by bacterial isolates purification using streak plate method. Screening of antibacterial activity using the agar plug method, as well as molecular identification was conducted by 16S rDNA PCR amplification. The results of this study indicated that a total of 26 bacterial strains were successfully isolated from sea cucumber intestine, consisted of eleven bacterial isolates from H. atra in Menjangan Besar waters and the rest fifteen isolates from H. atra in Alang-alang waters. The preliminary assay of antibacterial test showed H. atra in both waters have potential bacterial isolates. Those bacterial isolates with antibacterial activity were HM1.2 and HA1.1, which based on molecular identification, showed isolates HM1.2 and HA1.1 had the closest similarity with Bacillus paramcoides and Vibrio alginolyticus consecutively, with BLAST homology 98% and 99%. The accession number for both isolates were LC550090 and LC550089, respectively.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Prashantha M K ◽  
Shambulingappa B E ◽  
Sundareshan S ◽  
Kotresh A M ◽  
Rudresh B H ◽  
...  

Shivamogga. Exudate/pus/lesion swabs were collected from clinical cases of canine pyoderma (n=126) and subjected to isolation and identification of bacterial isolates by phenotypic methods. The bacteriological processing of the samples resulted in the recovery of 95 staphylococcal isolates and 18 other bacterial isolates. On culture, staphylococci were the most predominantly (n=95, 75.39%) isolated organisms. The PCR was employed as molecular method in this study for the detection of species of staphylococcal isolates by targeting nuc gene and it was also used for the detection of virulence gene and antibiotic resistance gene in staphylococcal isolates by targeting siet gene and mecA gene, respectively, by using primers published earlier. One of the S. pseudintermedius isolates which confirmed by PCR and sequencing of partial nuc gene was used as positive reference strain for further screening of isolates by PCR. Based on nuc gene-based PCR, out of 95 staphylococcal isolates obtained, 82 (86.1%)of the isolates were found belonging to S. pseudintermedius. And out of 82 S. pseudintermedius isolates, siet gene was detected in 69 (86.1%) isolates. S. pseudintermedius was found to be predominant bacterial pathogen responsible for pyoderma in dogs.


2017 ◽  
Vol 14 (3) ◽  
pp. 1129-1134
Author(s):  
Jyothi Kshatri ◽  
C.V. Rao ◽  
Vijaya Saradhi Settaluri

ABSTRACT: Aquaculture also known as fish farming is one of the methods for breeding rearing and harvesting of freshwater and marine species of fish and shellfish, in ponds, rivers, lakes and oceans. In this article an attempt has been put forth to study and apply techniques that could help in improving the water quality in aquaculture ponds and to further understand the role played by enzymes and probiotics by means of bio remedial procedures and protocols. Aquaculture productivity needs to be improved to cater the ever-increasing demand, no doubt, but simultaneously a proactive role for environment protection is required. The gathering of organic wastes worsens the water quality and reduces the level of dissolved oxygen in the fish aquaculture ponds. This further increases the formation of toxic metabolites such as ammonia (NH3), nitrite (NO2-) and hydrogen sulphide (H2S). Hence, NH4+ or NO3- removal processes (nitrification and denitrification) become essential for the pond water quality. This can be carried out by applying different types of nitrifying and denitrifying bacteria such as Nitrosomonas, Nitrobacter and Alcaligenes. In the present investigation, 2 earthen ponds were selected from Ponnagi near Eluru in Krishna district, Andhra Pradesh, India. One pond (Pond A) was treated with probiotics having Nitrosomonas, Nitrobacter and Alcaligenes sps. And the other pond (Pond B) was kept as control. During the culture period, the water samples were collected from probiotics treated and control ponds for analysis of water quality parameters. The current study is aimed to focus on the changes in water quality and biochemical characterization of bacterial isolates from water samples of Ponnagi area in probiotic treated ponds and to compare the results with ponds not treated with probiotics.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Søren Brander ◽  
Stine Lausten ◽  
Johan Ø. Ipsen ◽  
Kristoffer B. Falkenberg ◽  
Andreas B. Bertelsen ◽  
...  

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are important industrial enzymes known for their catalytic degradation of recalcitrant polymers such as cellulose or chitin. Their activity can be measured by lengthy HPLC methods, while high-throughput methods are less specific. A fast and specific LPMO assay would simplify screening for new or engineered LPMOs and accelerate biochemical characterization. Results A novel LPMO activity assay was developed based on the production of the dye phenolphthalein (PHP) from its reduced counterpart (rPHP). The colour response of rPHP oxidisation catalysed by the cellulose-specific LPMO from Thermoascus aurantiacus (TaAA9A), was found to increase tenfold by adding dehydroascorbate (DHA) as a co-substrate. The assay using a combination of rPHP and DHA was tested on 12 different metallo-enzymes, but only the LPMOs catalysed this reaction. The assay was optimized for characterization of TaAA9A and showed a sensitivity of 15 nM after 30 min incubation. It followed apparent Michaelis–Menten kinetics with kcat = 0.09 s−1 and KM = 244 µM, and the assay was used to confirm stoichiometric copper–enzyme binding and enzyme unfolding at a temperature of approximately 60 °C. DHA, glutathione and fructose were found to enhance LPMO oxidation of rPHP and in the optimized assay conditions these co-substrates also enabled cellulose degradation. Conclusions This novel and specific LPMO assay can be carried out in a convenient microtiter plate format ready for high-throughput screening and enzyme characterization. DHA was the best co-substrate tested for oxidation of rPHP and this preference appears to be LPMO-specific. The identified co-substrates DHA and fructose are not normally considered as LPMO co-substrates but here they are shown to facilitate both oxidation of rPHP and degradation of cellulose. This is a rare example of a finding from a high-throughput assay that directly translate into enzyme activity on an insoluble substrate. The rPHP-based assay thus expands our understanding of LPMO catalysed reactions and has the potential to characterize LPMO activity in industrial settings, where usual co-substrates such as ascorbate and oxygen are depleted.


Author(s):  
Ardiansyah Kurniawan ◽  
Asep Awaludin Prihanto ◽  
Suci Puspita Sari ◽  
Andi Kurniawan ◽  
Euis Asriani ◽  
...  

Acceleration of wood weathering in the mangrove area is possible with the role of cellulolytic bacteria. Cellulolytic bacteria producing cellulase enzymes are needed by the animal feed and agriculture industries. Mangroves in Muntok Subdistrict undergo a process of adaptation to environmental changes due to tin mining, including microorganisms. Exploration of new species and strains of cellulolytic bacteria in miningaffected mangroves is needed to enrich the collection and its potential use for human needs. This study aims to identify cellulolytic bacteria in mangrove weathered wood in Muntok District, West Bangka Regency through isolation, screening, and biochemical characterization. Three sampling locations, namely Sukal Mangrove, Peltim Mangrove, and Tembelok Mangrove result 22 bacterial isolates with 11 isolates showing the ability of cellulose degradation in qualitative tests using Lugol. The biochemical characterization of bacterial isolates with the greatest cellulose degradation was directed towards Citrobacter freundii and Vibrio alginolyticus in samples of Sukal Mangrove and Actinomyces bovis in isolates from Peltim Mangrove.


Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.


2014 ◽  
Vol 3 (3) ◽  
pp. 218-225
Author(s):  
R. G. Somkuwar ◽  
M. A. Bhange ◽  
A. K. Upadhyay ◽  
S. D. Ramteke

SauvignonBlanc wine grape was characterized for their various morphological, physiological and biochemical parameters grafted on different rootstocks. Significant differences were recorded for all the parameters studied. The studies on vegetative parameters revealed that the rootstock influences the vegetative growth thereby increasing the photosynthetic activities of a vine. The highest photosynthesis rate was recorded in 140-Ru grafted vine followed by Fercal whereas the lowest in Salt Creek rootstock grafted vines.The rootstock influenced the changes in biochemical constituents in the grafted vine thereby helping the plant to store enough food material. Significant differences were recorded for total carbohydrates, proteins, total phenols and reducing sugar. The vines grafted on1103-Pshowed highest carbohydrates and starch followed by 140-Ru,while the least amount of carbohydrates were recorded in 110-R and Salt Creek grafted vines respectively.Among the different rootstock graft combinations, Fercal showed highest amount of reducing sugar, proteins and phenols, followed by 1103-P and SO4, however, the lowest amount of reducing sugar, proteins and phenols were recorded with 110-R grafted vines.The vines grafted on different rootstocks showed changes in nutrient uptake. Considering this, the physico-biochemical characterization of grafted vine may help to identify particularrootstocks combination that could influence a desired trait in commercial wine grape varieties after grafting.


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