From martin.rao from gmail.com Wed Jul 16 01:33:39 2008 From: martin.rao from gmail.com (martin rao) Date: Wed Jul 16 08:36:23 2008 Subject: [Microbiology] Contamination of 7H11 agar plates Message-ID: Hello Laurn. I came across your email on a blogspot by chance and thought that you might be able to offer help with my problem. My lab work mainly involves mycobacteriology and using 7H11 agar for plating is somewhat routine. Very recently, I have been facing serious problems with contamination on unused agar plates and I am rather perplexed as to how this could be. Of course, contamination on agar is quite common a phenomenon but having said that, the nature of the contamination seems puzzling. There happen to be grain-like bacterial colonies seeded evenly within the agar, with a substantial number of morphologically different colonies growing on the surface of the medium. They are all white in colour, though the surface-growers have a characteristic 'shiny, appearance. I am also told that this type of bacterial colonies are also known as 'pressed-coin'. I haven't been all that successful in deciphering this issue online and so, I wonder if you could help me at all. Also, I must point out here that everyone in the lab where I work uses the same autoclave machine. In addition, the supplementary reagents that I add to molten agar prior to pouring plates are as well those used for preparing liquid medium (7H9 broth) and I find not contamination there, whatsoever. I look forward to hearing from you. Sincerely, Martin From aysein9 from yahoo.com Wed Jul 16 03:56:21 2008 From: aysein9 from yahoo.com (=?iso-8859-1?Q?ayse_=DDnhan_Garip?=) Date: Wed Jul 16 08:44:12 2008 Subject: [Microbiology] Dr.Ross, info request from istanbul Message-ID: <975459.89220.qm@web31303.mail.mud.yahoo.com> Dear Dr. Ross, I got your adress from bio.net. I want to determine GroEL and Dnak in gram positive and gram negative bacteria under various conditions with western blot. I need a housekeeping gene to normalize my results. I would appreciate very much if you could suggest me one. Thank you for very much for all the trouble. Kind regards, Ayse Inhan (Marmara Univ. School of Medicine , Biophysics Dept.) From bactitech from nospamhortonsbay.com Wed Jul 16 23:45:02 2008 From: bactitech from nospamhortonsbay.com (JEDilworth) Date: Thu Jul 17 12:20:39 2008 Subject: [Microbiology] Re: Contamination of 7H11 agar plates References: Message-ID: Have you tried subculturing these colony types to another type of general laboratory medium, like TSA or TSA with 5% sheep blood to see what they are? Have you tried staining these to see what they are? Are they acid fast? I would think that 7H11 would grow regular bacteria, as I do not believe that it has any antibiotics in it to inhibit non-acid fast bacterial growth. If they are some sort of Bacillus sp. then your medium is not being properly sterilized by your autoclave. Have you run controls on your autoclave to make sure that it is getting to the right temperature? You can buy commercial autoclave controls in various formats. How long are you sterilizing for? Are the plates you are pouring into sterile? Are you pouring into plates that have had the package opened for quite some time? Are you somehow introducing something nonsterile into your medium after you autoclave but before you pour? You're not stirring the medium with anything that is not sterile, are you? Do you cover your flask in the autoclave? We used to put gauze over the top of the flask and seal with autoclave tape. This let the steam out but kept stuff from falling into the media while it cooled off in the 56 degree water bath until we poured. Hopefully your flask is not open to the air in the time between autoclaving and pouring. If it is down in the agar then it is a sterilization problem. I've never made 7H11 - always used commercially made plates - so don't know how tricky it is to make. If your supplements don't produce contamination in your 7H9 broth, then the only explanation is that your autoclave is not functioning correctly and your media is not properly sterilized or you are introducing a contaminant post-autoclaving. Good luck. Judy Dilworth, M.T. (ASCP) Microbiology "martin rao" wrote in message news:mailman.757.1216215400.3533.microbio@net.bio.net... > Hello Laurn. > > I came across your email on a blogspot by chance and thought that you > might > be able to offer help with my problem. My lab work mainly involves > mycobacteriology and using 7H11 agar for plating is somewhat routine. > Very > recently, I have been facing serious problems with contamination on > unused > agar plates and I am rather perplexed as to how this could be. From crisruzene from gmail.com Thu Jul 17 03:08:31 2008 From: crisruzene from gmail.com (crisruzene) Date: Thu Jul 17 12:22:09 2008 Subject: [Microbiology] Halophiles..? Message-ID: <572252ae-574c-485b-9521-509928dc8a34@56g2000hsm.googlegroups.com> Hello there! Is anyone here doing research on halophiles? I'm working on my Master thesis and planning to do my PhD on this...I need contacts..! Thank you for your time, cheers C.R.N. From tmccloud57 from sprintpcs.com Thu Jul 17 15:33:25 2008 From: tmccloud57 from sprintpcs.com (tmccloud57@sprintpcs.com) Date: Thu Jul 17 16:11:17 2008 Subject: [Microbiology] Re: Contamination of 7H11 agar plates References: Message-ID: <2oav74prmh7iruec7if4nintfbgg05a809@4ax.com> A plant pathologist I know, who brings plants into the lab and cultures microbes from them, had a long-unexplained, un-inoculated Petri dish contamination problem until he started storing plates in deep, sterilized plastic tubs. Turns out mites, so small you don't normally see them, were crawling around, carrying microbes into everything. Choose tubs big enough so mites can't climb into them. Good luck, Tom McCloud On Wed, 16 Jul 2008 14:33:39 +0800, "martin rao" wrote: >Hello Laurn. > >I came across your email on a blogspot by chance and thought that you might >be able to offer help with my problem. My lab work mainly involves >mycobacteriology and using 7H11 agar for plating is somewhat routine. Very >recently, I have been facing serious problems with contamination on unused >agar plates and I am rather perplexed as to how this could be. Of course, >contamination on agar is quite common a phenomenon but having said that, the >nature of the contamination seems puzzling. There happen to be grain-like >bacterial colonies seeded evenly within the agar, with a substantial number >of morphologically different colonies growing on the surface of the medium. >They are all white in colour, though the surface-growers have a >characteristic 'shiny, appearance. I am also told that this type of >bacterial colonies are also known as 'pressed-coin'. I haven't been all that >successful in deciphering this issue online and so, I wonder if you could >help me at all. Also, I must point out here that everyone in the lab where I >work uses the same autoclave machine. In addition, the supplementary >reagents that I add to molten agar prior to pouring plates are as well those >used for preparing liquid medium (7H9 broth) and I find not contamination >there, whatsoever. > >I look forward to hearing from you. > >Sincerely, >Martin From htmboost from inet.polyu.edu.hk Fri Jul 18 02:40:03 2008 From: htmboost from inet.polyu.edu.hk (Maureen Boost [HTI]) Date: Fri Jul 18 07:58:44 2008 Subject: [Microbiology] Re: Contamination of 7H11 agar plates References: <2oav74prmh7iruec7if4nintfbgg05a809@4ax.com> Message-ID: <20080718T154003Z_593900020000@inet.polyu.edu.hk> We have also have the insect problem -but that led to "trails" of colonies rather than evenly seeded throughout . This sounds more like something in the agar - if other people using the same autoclave have no problem - are you filtering your additives with .22 filters and have the filter holders been properly sterilised? Otherwise are you using a dispenser to fill the petri dishes - check that tubing is regularly sterilised. Maureen >>> 18/07/2008 4:33 AM >>> A plant pathologist I know, who brings plants into the lab and cultures microbes from them, had a long-unexplained, un-inoculated Petri dish contamination problem until he started storing plates in deep, sterilized plastic tubs. Turns out mites, so small you don't normally see them, were crawling around, carrying microbes into everything. Choose tubs big enough so mites can't climb into them. Good luck, Tom McCloud On Wed, 16 Jul 2008 14:33:39 +0800, "martin rao" wrote: >Hello Laurn. > >I came across your email on a blogspot by chance and thought that you might >be able to offer help with my problem. My lab work mainly involves >mycobacteriology and using 7H11 agar for plating is somewhat routine. Very >recently, I have been facing serious problems with contamination on unused >agar plates and I am rather perplexed as to how this could be. Of course, >contamination on agar is quite common a phenomenon but having said that, the >nature of the contamination seems puzzling. There happen to be grain-like >bacterial colonies seeded evenly within the agar, with a substantial number >of morphologically different colonies growing on the surface of the medium. >They are all white in colour, though the surface-growers have a >characteristic 'shiny, appearance. I am also told that this type of >bacterial colonies are also known as 'pressed-coin'. I haven't been all that >successful in deciphering this issue online and so, I wonder if you could >help me at all. Also, I must point out here that everyone in the lab where I >work uses the same autoclave machine. In addition, the supplementary >reagents that I add to molten agar prior to pouring plates are as well those >used for preparing liquid medium (7H9 broth) and I find not contamination >there, whatsoever. > >I look forward to hearing from you. > >Sincerely, >Martin _______________________________________________ Microbio mailing list Microbio@net.bio.net http://www.bio.net/biomail/listinfo/microbio From farrlarr from isu.edu Fri Jul 18 10:15:25 2008 From: farrlarr from isu.edu (Larry Farrell) Date: Fri Jul 18 12:01:29 2008 Subject: [Microbiology] Re: Contamination of 7H11 agar plates In-Reply-To: References: Message-ID: <44464$4880b38e$10382@news.teranews.com> martin rao wrote: [snip] Very > recently, I have been facing serious problems with contamination on unused > agar plates and I am rather perplexed as to how this could be. Of course, > contamination on agar is quite common a phenomenon but having said that, the > nature of the contamination seems puzzling. There happen to be grain-like > bacterial colonies seeded evenly within the agar, with a substantial number > of morphologically different colonies growing on the surface of the medium. > They are all white in colour, though the surface-growers have a > characteristic 'shiny, appearance. I am also told that this type of > bacterial colonies are also known as 'pressed-coin'. I haven't been all that > successful in deciphering this issue online and so, I wonder if you could > help me at all. Also, I must point out here that everyone in the lab where I > work uses the same autoclave machine. In addition, the supplementary > reagents that I add to molten agar prior to pouring plates are as well those > used for preparing liquid medium (7H9 broth) and I find not contamination > there, whatsoever. [snip] From what you have described, it is clear that either bacteria in your agar are not being killed by the autoclaving or you are introducing contaminants by additions to the agar after autoclaving. Those are the only ways you are going to see both surface and sub-surface colonies; the bacteria have to be distributed throughout the agar when it is poured to produce the pattern you describe. Others have suggested ways to check autoclave operation, although I note that you say others use the same autoclave and (apparently) are not experiencing contamination problems. You also state that you use the same supplements in broth without any growth occurring. Since I am not familiar with the media you are using, I ask whether *all* supplements are used in both agar and broth? Is the *only* difference between agar and broth the presence of agar? If so, that really leaves only the autoclaving as the possible culprit (unless you are doing something really strange, such as possibly using non-sterile pipets, etc, to add supplements to the agar; that really makes no sense but it is all I can come up with as an additional possibility). -- Larry D. Farrell, Ph.D. Professor Emeritus of Microbiology Idaho State University ** Posted from http://www.teranews.com ** From karbalaeei from yahoo.com Sat Jul 19 09:25:46 2008 From: karbalaeei from yahoo.com (gh reza karbalaei) Date: Sat Jul 19 21:24:28 2008 Subject: [Microbiology] question Message-ID: <905427.62426.qm@web90307.mail.mud.yahoo.com> Hello I research gram negative bacteria, but I need some information about B. subtilis that I cannot seem to find. I was wondering if anyone could answer some basic questions about this organism and possibly point me to some good review articles about the genetic manipulation and protocols for in in vitro growth. Questions: 1) What is the composition of Difco sporulation media? I checked Difco and BD website but couldn't find this product. A google search also yielded no results. I could find no recipe. 2) Why does sporulation medium induce sporulation? Are there less nutrients present? 3) Does B. subtilis grow better at 30 C or 37 C? Thanks for helping me out. From karbalaeei from yahoo.com Sun Jul 20 01:47:00 2008 From: karbalaeei from yahoo.com (gh reza karbalaei) Date: Sun Jul 20 06:06:55 2008 Subject: [Microbiology] question about B. subtilis spore Message-ID: <479232.41509.qm@web90301.mail.mud.yahoo.com> Hello I research gram negative bacteria, but I need some information about B. subtilis that I cannot seem to find. I was wondering if anyone could answer some basic questions about this organism and possibly point me to some good review articles about the genetic manipulation and protocols for in in vitro growth. Questions: 1) What is the composition of Difco sporulation media? I checked Difco and BD website but couldn't find this product. A google search also yielded no results. I could find no recipe. 2) Why does sporulation medium induce sporulation? Are there less nutrients present? 3) Does B. subtilis grow better at 30 C or 37 C? Thanks for helping me out. From bactitech from nospamhortonsbay.com Sun Jul 20 22:08:00 2008 From: bactitech from nospamhortonsbay.com (JEDilworth) Date: Mon Jul 21 06:32:28 2008 Subject: [Microbiology] Re: question about B. subtilis spore References: Message-ID: Bacillus subtilis is a gram positive rod last time I checked. Judy Dilworth, M.T. (ASCP) Microbiology "gh reza karbalaei" wrote in message news:mailman.828.1216552105.3533.microbio@net.bio.net... > I research gram negative bacteria, but I need some information about > B. subtilis that I cannot seem to find. From agonzalez01 from mail.rockefeller.edu Mon Jul 21 10:53:27 2008 From: agonzalez01 from mail.rockefeller.edu (adriana gonzalez) Date: Mon Jul 21 21:35:26 2008 Subject: [Microbiology] Help in making molar solutions Message-ID: <4C70977F-2F61-4BA1-BD07-E134628A43A5@rockefeller.edu> Could you please help me figure out how to prepare a 1M solution of NaCl. And how to prepare a 120mM solution from the IM stock. Thank you. Adriana Gonzalez From limbic_lesion from hotmail.com Mon Jul 21 18:31:22 2008 From: limbic_lesion from hotmail.com (N10) Date: Mon Jul 21 21:35:29 2008 Subject: [Microbiology] Re: question about B. subtilis spore References: Message-ID: Greetings 1) What is the composition of Difco sporulation media? I checked Difco and BD website but couldn't find this product. A google search also yielded no results. I could find no recipe. A bit more effort needed on your part on this one as the information is in the Difco manual. These can be purchased on line. 2) Why does sporulation medium induce sporulation? Are there less nutrients present? Its a nutrient defficient medium which becomes rapdily depleted thus inducing sporulation. 3) Does B. subtilis grow better at 30 C or 37 C? Depends on the strain and medium used . Why not set up an experiment to determine optimal growth for the strains you are working with. Also Judy is correct B.subtilis is Gram positive. Best N10 "gh reza karbalaei" wrote in message news:mailman.828.1216552105.3533.microbio@net.bio.net... > Hello > I research gram negative bacteria, but I need some information about B. > subtilis that I cannot seem to find. I was wondering if anyone could > answer some basic questions about this organism and possibly point me to > some good review articles about the genetic manipulation and protocols for > in in vitro growth. > > Questions: > > 1) What is the composition of Difco sporulation media? I checked Difco and > BD website but couldn't find this product. A google search also yielded no > results. I could find no recipe. > 2) Why does sporulation medium induce sporulation? Are there less > nutrients present? > 3) Does B. subtilis grow better at 30 C or 37 C? > > Thanks for helping me out. > > > From bactitech from nospamhortonsbay.com Mon Jul 21 23:19:14 2008 From: bactitech from nospamhortonsbay.com (JEDilworth) Date: Tue Jul 22 19:19:40 2008 Subject: [Microbiology] Re: Help in making molar solutions References: Message-ID: C'mon, Adriana. You're in college now. This is stuff from high school chemistry! Judy Dilworth, M.T. (ASCP) Microbiology and also a curmudgeon "adriana gonzalez" wrote in message news:mailman.842.1216694179.3533.microbio@net.bio.net... > Could you please help me figure out how to prepare a 1M solution of > NaCl. And how to prepare a 120mM solution from the IM stock. Thank > you. > Adriana Gonzalez > From hroychow from nmsu.edu Mon Jul 21 22:04:48 2008 From: hroychow from nmsu.edu (Dr. Hiranya S. Roychowdhury) Date: Tue Jul 22 19:19:49 2008 Subject: [Microbiology] Help in making molar solutions In-Reply-To: <4C70977F-2F61-4BA1-BD07-E134628A43A5@rockefeller.edu> References: <4C70977F-2F61-4BA1-BD07-E134628A43A5@rockefeller.edu> Message-ID: <1767.71.210.238.48.1216695888.squirrel@webmail.nmsu.edu> This is truly amazing! Amazing! Rockefeller.edu?! Really? *shaking my head in vigorous disbelief* .... > Could you please help me figure out how to prepare a 1M solution of > NaCl. And how to prepare a 120mM solution from the IM stock. Thank you. > Adriana Gonzalez > > _______________________________________________ > Microbio mailing list > Microbio@net.bio.net > http://www.bio.net/biomail/listinfo/microbio > -- Hiranya S. Roychowdhury, Ph.D. Asst. Professor, Health & Public Services Dona Ana Community College New Mexico State University Las Cruces, NM 88003 From GreenieLeBrun from hotmail.com Mon Jul 21 22:51:00 2008 From: GreenieLeBrun from hotmail.com (GreenieLeBrun) Date: Tue Jul 22 19:19:52 2008 Subject: [Microbiology] Re: Help in making molar solutions References: Message-ID: adriana gonzalez wrote: > Could you please help me figure out how to prepare a 1M solution of > NaCl. And how to prepare a 120mM solution from the IM stock. Thank > you. Adriana Gonzalez http://en.wikipedia.org/wiki/Molar_solution http://en.wikipedia.org/wiki/Molar_%28concentration%29 http://environmentalchemistry.com/yogi/reference/molar.html Didn't you pay attention in Secondary School Chemistry? From farrlarr from isu.edu Mon Jul 21 23:09:26 2008 From: farrlarr from isu.edu (Larry Farrell) Date: Tue Jul 22 19:19:56 2008 Subject: [Microbiology] Re: Help in making molar solutions In-Reply-To: References: Message-ID: <71333$48855d74$8023@news.teranews.com> GreenieLeBrun wrote: > adriana gonzalez wrote: >> Could you please help me figure out how to prepare a 1M solution of >> NaCl. And how to prepare a 120mM solution from the IM stock. Thank >> you. Adriana Gonzalez > > http://en.wikipedia.org/wiki/Molar_solution > > http://en.wikipedia.org/wiki/Molar_%28concentration%29 > > http://environmentalchemistry.com/yogi/reference/molar.html > > Didn't you pay attention in Secondary School Chemistry? > > Wow, someone besides me being a curmudgeon!! -- Larry D. Farrell, Ph.D. Professor Emeritus of Microbiology Idaho State University ** Posted from http://www.teranews.com ** From Jennifer.Keene from students.olin.edu Tue Jul 22 21:41:55 2008 From: Jennifer.Keene from students.olin.edu (Jennifer Keene) Date: Wed Jul 23 09:40:22 2008 Subject: [Microbiology] Re: Help in making molar solutions In-Reply-To: References: Message-ID: <81F8DFD002DFF14697B4F5FE420FEB680D598B2D@OLINEXVS01.olin.edu> You Should be able to do the dilution calculation on your own, but if you want a double check, google "dilution calculator" - its one of those things you discover when you're making solutions at 4 am half dead/asleep Cheers, Jen -----Original Message----- From: microbio-bounces@oat.bio.indiana.edu [mailto:microbio-bounces@oat.bio.indiana.edu] On Behalf Of JEDilworth Sent: Tuesday, July 22, 2008 12:19 AM To: microbio@magpie.bio.indiana.edu Subject: [Microbiology] Re: Help in making molar solutions C'mon, Adriana. You're in college now. This is stuff from high school chemistry! Judy Dilworth, M.T. (ASCP) Microbiology and also a curmudgeon "adriana gonzalez" wrote in message news:mailman.842.1216694179.3533.microbio@net.bio.net... > Could you please help me figure out how to prepare a 1M solution of > NaCl. And how to prepare a 120mM solution from the IM stock. Thank > you. > Adriana Gonzalez > _______________________________________________ Microbio mailing list Microbio@net.bio.net http://www.bio.net/biomail/listinfo/microbio From txl8326 from louisiana.edu Wed Jul 23 08:29:02 2008 From: txl8326 from louisiana.edu (Luzan Tatiana) Date: Wed Jul 23 09:40:48 2008 Subject: [Microbiology] Iron oxidizing bacteria Message-ID: <20080723132603.M68260@louisiana.edu> Did anybody obtained a pure culture of anaerobic autotrophic Iron oxidizing bacteria on agar plates(with nitrate as an electron acceptor) from the environmental samples? I am thinking about using the agar containg plates overlaid by the liquid media and incubate them in the anaerobic hood. If you had done anything like that please give me any tips. Thanks Tanya Luzan txl8326@louisiana.edu -- From me from inter.net Thu Jul 31 04:58:44 2008 From: me from inter.net (Peter) Date: Thu Jul 31 10:25:19 2008 Subject: [Microbiology] StatorSystems Message-ID: Can anyone tell me where MotX and MotY are localized in the sodium-dependent statorsystem? in the outer membran (Fukuoka 2006) or inner membran (McCarter 1994)? or could it be that it is difuse localized in periplasmatic room, without membran binding (Kojima 2008)?