From samiboy_4ever from yahoo.com Sun Mar 2 08:09:08 2008 From: samiboy_4ever from yahoo.com (merhawi debesai) Date: Mon Mar 3 02:02:37 2008 Subject: [Biofilms] Biofilm experiment questions Message-ID: <961205.72516.qm@web58405.mail.re3.yahoo.com> Hi, Thank you so much for your information in advance. Currently, I am working on the physico-chemical characterization of EPS from three strains of biofilm bacteria Pseudomonas aeruginosa, using QCM-D. Thus, I have questions: 1. On QCM-D data interpretation: i. frequency change --> adsorbed mass ii. energy of dissipation --> to visico-elastic property of the adsorbed mass. 2. The second question is regarding the preparation of bacterial strains for surface analysis. i. Usually, we prepare the test strains in suspensions. However, it is known that there....difference between planktonic and sessile (biofilm) bacteria. Thus,AREN'T WE TAKING THE WRONG STRAIN?! Sincerly yours, tesfalem --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.bio.net/bionet/mm/biofilms/attachments/20080302/8f23e0ae/attachment.html From bbx107 from excite.XXXX.com Tue Mar 4 23:20:22 2008 From: bbx107 from excite.XXXX.com (bob) Date: Wed Mar 5 03:12:41 2008 Subject: [Biofilms] Re: Biofilm experiment questions References: Message-ID: On Sun, 2 Mar 2008 05:09:08 -0800 (PST), merhawi debesai wrote: >Hi, > Thank you so much for your information in advance. > Currently, I am working on the physico-chemical characterization of EPS from three strains of biofilm bacteria Pseudomonas aeruginosa, using QCM-D. Thus, I have questions: > > 2. The second question is regarding the preparation of bacterial strains for > surface analysis. > i. Usually, we prepare the test strains in suspensions. However, it is > known that there....difference between planktonic and sessile (biofilm) > bacteria. Thus,AREN'T WE TAKING THE WRONG STRAIN?! I think you just answered your own question. Not sure if they make a different EPS when sessile, rather than just more of it. But seems to me you would want to at least check. Once you get your methodology running, try comparing. By the way, there is a nice overview article in February issue of Microbe: How Pseudomonas aeruginosa Regulates Surface Behaviors George A. O?Toole At surfaces, these bacteria either form biofilms or swarm, a regulated behavior with important consequences for pathogenesis http://www.asm.org/microbe/index.asp?bid=55982 bob From Ashkan.Safari from ucd.ie Tue Mar 11 11:14:32 2008 From: Ashkan.Safari from ucd.ie (Ashkan Safari) Date: Tue Mar 11 13:22:56 2008 Subject: [Biofilms] compression test on biofilm Message-ID: Dear all, I am a mechanical engineer who is measuring biofilm mechanical properties. I am currently doing compression tests on mixed biofilm. I have two questions: 1. Biofilm used in the test is a few weeks old, do I expect to see big difference in results when I do it on very fresh biofilm? 2. I had a 100N load cell and I know sensitivity is low, does it affect results in unacceptable way? 3. Biofilm is placed in a glass container and I have a surface tension problem and biofilm sticks to the glass wall, any recommendation to reduce adhesion? I used PTFE lubricant but didn't work well. Thanks in advance, Ashkan Safari PhD Research Student UCD School of Electrical, Electronic and Mechanical Engineering Room 314 University College Dublin Belfield Dublin 4 Ireland Ph: +353 1 716 1880 Mob: +353 860867511 E-mail: Ashkan.Safari@ucd.ie -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.bio.net/bionet/mm/biofilms/attachments/20080311/86e35ebd/attachment.html From samiboy_4ever from yahoo.com Tue Mar 11 03:40:45 2008 From: samiboy_4ever from yahoo.com (merhawi debesai) Date: Tue Mar 11 13:23:04 2008 Subject: [Biofilms] Thank you for your information on biofilm questins but i have more questions In-Reply-To: <200803051703.m25H3dL24350@net.bio.net> Message-ID: <457473.90613.qm@web58401.mail.re3.yahoo.com> Thank you so much for your brief information on the previous biofilm questions. I also have another question. Q. usually, procedures followed in the lab for bacterial surface analysis are destructive to the bacterial surface composition which might ofcourse lead to wrong conclusion. - Washing procedure - Type of washing and resuspension medium used - Speed of centrifugation Thus, does any body have any idea on how to handle these procedures so that to minimize the damage? thank you so much agian. tesfalem biofilms-request@oat.bio.indiana.edu wrote: Send Biofilms mailing list submissions to biofilms@net.bio.net To subscribe or unsubscribe via the World Wide Web, visit http://www.bio.net/biomail/listinfo/biofilms or, via email, send a message with subject or body 'help' to biofilms-request@net.bio.net You can reach the person managing the list at biofilms-owner@net.bio.net When replying, please edit your Subject line so it is more specific than "Re: Contents of Biofilms digest..." Today's Topics: 1. Re: Biofilm experiment questions (bob) ---------------------------------------------------------------------- Message: 1 Date: Tue, 04 Mar 2008 20:20:22 -0800 From: bob Subject: [Biofilms] Re: Biofilm experiment questions To: bionet-microbiology-biofilms@magpie.bio.indiana.edu Message-ID: Content-Type: text/plain; charset=ISO-8859-1 On Sun, 2 Mar 2008 05:09:08 -0800 (PST), merhawi debesai wrote: >Hi, > Thank you so much for your information in advance. > Currently, I am working on the physico-chemical characterization of EPS from three strains of biofilm bacteria Pseudomonas aeruginosa, using QCM-D. Thus, I have questions: > > 2. The second question is regarding the preparation of bacterial strains for > surface analysis. > i. Usually, we prepare the test strains in suspensions. However, it is > known that there....difference between planktonic and sessile (biofilm) > bacteria. Thus,AREN'T WE TAKING THE WRONG STRAIN?! I think you just answered your own question. Not sure if they make a different EPS when sessile, rather than just more of it. But seems to me you would want to at least check. Once you get your methodology running, try comparing. By the way, there is a nice overview article in February issue of Microbe: How Pseudomonas aeruginosa Regulates Surface Behaviors George A. O?Toole At surfaces, these bacteria either form biofilms or swarm, a regulated behavior with important consequences for pathogenesis http://www.asm.org/microbe/index.asp?bid=55982 bob ------------------------------ _______________________________________________ Biofilms mailing list Biofilms@net.bio.net http://www.bio.net/biomail/listinfo/biofilms End of Biofilms Digest, Vol 16, Issue 2 *************************************** --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.bio.net/bionet/mm/biofilms/attachments/20080311/076298d8/attachment.html From sandalindra from yahoo.com Thu Mar 13 10:52:44 2008 From: sandalindra from yahoo.com (Sandal, Indra) Date: Thu Mar 13 12:50:32 2008 Subject: [Biofilms] RNA isolation from biofilm Message-ID: <227514.12100.qm@web53009.mail.re2.yahoo.com> Dear all: What's the best way to isolate the RNA from biofilm for RT PCR. ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping From DrKJRoberts from gmail.com Mon Mar 31 13:01:45 2008 From: DrKJRoberts from gmail.com (DrKJRoberts@gmail.com) Date: Mon Mar 31 13:15:05 2008 Subject: [Biofilms] 59th Annual International Science and Engineering Fair - Call for Judges Message-ID: The 59th ISEF will be held this year in Atlanta, Georgia May 11th-17th. I am looking for volunteers to serve as Grand Awards Judges in the Microbiology Category. Last year's ISEF in Albuquerque, New Mexico, over 45 different countries sent 1510 secondary school finalists to compete. We expect the same turn out at this year's Fair. I am looking for judges to choose the top finalists who will compete for thousands of dollars in prizes and awards. Grand Awards Judges will arrive in Atlanta on Tuesday, May 13 for orientation and pre-judging and will judge on Wednesday, May 14. This is the premier worldwide science research competition for high school students grades 9-12 and we need your support. If you are interested in serving as a judge at this year's ISEF, please go to the following website and register: http://www.intelisef2008.org/judging.html If you need more information, don't hesitate to contact me at drkjroberts@gmail.com Karl J. Roberts, Ph.D. Co-Chair, Microbiology Division International Science and Engineering Fair