scholarly journals Novel alkaline protease of Staphylococcus cohnii N3 isolated from poultry farm soil used for silver recovery from waste X-ray film

2021 ◽  
Vol 7 (6) ◽  
pp. 238-243
Author(s):  
S Radhathirumalaiarasu ◽  
I Parveen Taj
Author(s):  
S Shankar ◽  
SV More ◽  
R Seeta Laxman

The waste X-ray/ photographic films contain 1.5 - 2 % (w/w) black metallic silver which isrecovered and reused. Around 18-20% of the world's silver needs are supplied by recyclingphotographic waste. Since silver is linked to gelatin in the emulsion layer, it is possible to break thesame and release the silver using proteolytic enzymes. Alkaline protease from Conidioboluscoronatus was investigated for enzymatic hydrolysis of gelatin from waste X-ray films. At the endof the treatment, gelatin layer was completely removed leaving the polyester film clean and silverwas recovered in the hydrolysate, both of which can be reused. Various parameters such as pH,temperature, enzyme concentration, time etc on silver removal from the film were studied. Gelatinhydrolysis was monitored by measuring increase in turbidity in the hydrolysate, which wasaccompanied by release of protein and hydroxyproline. Gelatin layer was stripped completelywithin 6 min with 1.35 U ml-1 of protease at 40°C, pH 10. Rate of gelatin hydrolysis increased withincreased in protease concentration. The enzyme could be effectively reused for four cycles ofgelatin hydrolysis. Silver in hydolysate was around 3.87% (w/w) based on total weight of sludge.Key words: Silver recovery; X-ray films; gelatin hydrolysis; alkaline protease; Conidiobolus coronatusDOI: 10.3126/kuset.v6i1.3311 Kathmandu University Journal of Science, Engineering and Technology Vol.6(1) 2010, pp60-69


2016 ◽  
Vol 15 (26) ◽  
pp. 1413-1416 ◽  
Author(s):  
Hassan Al Abdalall Amira ◽  
Marshid Al Khaldi Eida

2005 ◽  
Vol 18 (13-14) ◽  
pp. 1269-1276 ◽  
Author(s):  
K.G. Adani ◽  
R.W. Barley ◽  
R.D. Pascoe

1996 ◽  
Vol 235 (3) ◽  
pp. 606-612 ◽  
Author(s):  
Silvia Morante ◽  
Lars Furenlid ◽  
Giampietro Schiavo ◽  
Fiorella Tonello ◽  
Robert Zwilling ◽  
...  

2019 ◽  
pp. 1-8
Author(s):  
Tapasi Polley ◽  
Uma Ghosh

Aim: The current study aimed at studying the optimum fermentation conditions and nutritional conditions for alkaline protease production by submerge fermentation using Alternaria alternata TUSGF1, isolated from poultry farm soil. Study Design: The results of environmental and nutritional parameters for protease production by OVAT method was analyzed by origin 6.1 software. Place and Duration of Study: Department of Food technology and Biochemical Engineering, Jadavpur University, Kolkata, West Bengal, India between March 2017 and May 2017. Methodology: A protease producing microorganism was isolated from a poultry farm soil and identified as Alternaria alternata TUSGF1. Various environmental and nutritional process parameters such as volume of medium, fermentation time, temperature, age of inoculums, agitation and carbon sources and nitrogen sources were standardized for the maximum yield of alkaline protease. Results: The optimum conditions of protease activity was 30°C at volume of medium 60 ml with 7 days age of inoculum in the medium containing 168 h of incubation and 120 rpm agitation rate. Peptone, casien, skimmed milk, urea and yeast extract were good nitrogen sources whilst maltose, fructose, starch, and sucrose were appropriate for enzyme production by submerge fermentation. Conclusion: Alkaline protease production by a newly isolated Alternaria alternata TUSGF1 from poultry farm soil was studied in shake flask conditions by submerge fermentation. It was established that the optimum protease production was recorded at 30°C, 60 ml volume of medium leaves and incubation time of 168 h. The best carbon and nitrogen sources for protease production were fructose and casein, respectively.


2017 ◽  
Vol 7 (5) ◽  
pp. 2094-2097
Author(s):  
V. R. K. R. Galarpe ◽  
G. D. Leopoldo

The study aims to establish a chemical method of silver recovery from x-ray processing fixer waste by alkaline treatment using sodium hydroxide (NaOH). The samples used in the study were collected from selected hospitals and radiology centers in Cagayan de Oro City, Philippines. The NaOH precipitation method was employed by varying the amount of NaOH from 8.00 g to 15.00 g per 600 mL of the fixer waste sample. The recovered crude silver for the two sampling periods ranged from 0.88 g to 2.46 g. The method resulted to optimum recovery at pH 9. The One Way ANOVA indicates that there are significant differences on the amount of silver recovered when varying the amount of NaOH in “sampling A”. The Tukey Test further reveals that there exists an evident rise in the recovered silver using 10.00 g to 15.00 g of NaOH. In “sampling B” the amount of silver recovered does not significantly differ when varying the amount of NaOH used on average basis. The raw data, however, also revealed a significant rise in the amount of silver recovered using 10.00 g to 15.00 g of NaOH where pH was approximately 9.


2015 ◽  
Vol 5 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Shiv Shankar ◽  
R.G.S.V. Prasad ◽  
P.R. Selvakannan ◽  
Lily Jaiswal ◽  
R.S. Laxman

1973 ◽  
Vol 75 (4) ◽  
pp. 745-IN22 ◽  
Author(s):  
Yoshinori Satow ◽  
Yukio Mitsui ◽  
Yoichi Iitaka ◽  
Sawao Murao ◽  
Sakae Sato

1988 ◽  
Vol 204 (3) ◽  
pp. 803-804 ◽  
Author(s):  
Christian Betzel ◽  
Zbigniew Dauter ◽  
Miroslawa Dauter ◽  
Margareta Ingelman ◽  
Gerlind Papendorf ◽  
...  

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