“MUHITI GIZOi”

«MUHITI GIZOi, mabda (substrat)-i sunie, ki baroi rushdu inkishofi mikroorganizmho moddahoi zaruri dorad. Baroi omuzishi khususiyathoi mikroorganizmho (az jumla dar mavridi tahqiqi bakteriaologii bemorihoi siroyati), ba dast ovardani vaksinaho, antibiotikho va g. kor mefarmoyand.
Baroi rushdu inkishof mikroorganizmho boyad az M. g. miqdori zarurii moddahoi gizobakhshro girand. Onho ba gidrogen, oksigen, karbon, nitrogen, sulfur, fosfor, kaliy, magniy, kalsiy, ohan, inchunin ba mikroelementho – mangan, kobalt, mis., molibden, ruh, ki vazifai katalizatorhoi reaksiyahoi khimiyaviro ijro mekunand, ehtiyoj dorand. Baroi kishti bisyor mikroorganizmho omilhoi bakteriyavii rushd, yane moddahoi gizoii organiki, ki khudi onho nametavonand hosil bikunand, zarur meboshand (mas., aminokislotaho, vitaminho). Talaboti muhimi digar baroi M. g. dar sathi muayyanu musoid nigoh doshtani reaksiyai muhit ast. Doirai qimmati pH, ki dar holathoi gunogun istifoda meshavad, khele kalon, az 4,0 to 9,0 meboshad. Baroi bisyor bakteriyahoi bemorizo reaksiyai nisbatan muvofiqi muhit 7,2 – 7,4 ast. Dar natijai metabolizmi mikroorganizmho M. g. tursh yo ishqori meshavad, binobar in rushdi minbadai onho qat megardad. Baroi on ki reaksiya tagyir nayobad, ba M. g. mahlulhoi buferi (beshtar fosfati) ilova menamoyand. M. g. boyad ba miqdori kofi namnok va tamyizi boshad.
M. g. moe, galiz va nimmoe meshavad. Ba M. g.-i moe bulyoni gushtupeptoni va bulyoni qandi mansuband. M. g.-i galiz az 1 – 2% agari gushtupeptoni va zardobi lakhta tarkib yoftaast. M. g.-i nimmoe az 0,2 – 0,5% agari gushtupeptoni iborat meboshad. Baroi hosil kardani M. g.-i galiz ba muhiti moe, odatan, agar-agar (polisakharide, ki az obsabzhoi bahri megirand) yo jelatin (moddai tabiatash safedavii hayvoni) hamroh menamoyand.
Vobasta ba tarkib M. g. soda va murakkab meshavad. Ba M. g.-i soda (asosi) bulyoni gushtupeptoni, agari gushtupeptoni, obi peptoni va jelatin mansuband. Bulyoni gushtupeptoniro az obi gushti gov, ki ba on pepton (mahluli tajziyai nopurrai safedaho) va namaki oshi ilova karda meshavad, tahiya mesozand. Baroi ba dast ovardani agari gushtupeptoni ba bulyoni gushtupeptoni agar-agar hamroh menamoyand. In guna M. g.-ro baroi on asosi menomand, ki dar onho mikrobhoi bisyorro parvarish kardan mumkin ast. Gayr az in dar asosi onho M. g.-i murakkab tahiya karda meshavad, mas., bulyoni qandi, agari zardobi va g. M. g.-i murakkab baroi kishti mikroorganizmhoi nisbatan sertalab, ki dar muhiti muqarrari rushd nameyoband, istifoda meshavad. CHunonchi, streptokokk faqat dar muhiti qandi bo ilova kardani glyukoza mesabzad.
Az rui tainot M. g. khostgor (elektivi), toza va tashkhisi tafriqavi meshavad. Dar M. g.-i khostgor rushdi yak yo chand namudi mikroorganizmhoi ba hamdigar nazdikro tamin karda, rushdi mikroorganizmhoi begonaro furu menishonand. Misoli muhiti khostgor baroi salmonellaho va shigellaho bulyoni talkha (az talkha va bulyoni gushtupeptoni tarkib yoftaast), baroi vibrioni vabo obi ishqorii peptoni ast. Dar baze holatho muhiti khostgorro bo rohi ba M. g. ilova namudani antibiotikho ba dast meovarand. Muhiti toza ba muhiti khostgor nazdik ast. Odatan, dar on moddahoe, ki rushdi mikroorganizmhoro furu menishonand, vujud nadorand; dar on faqat baroi in yo on mikroorganizme, ki dar omekhta mavjud ast, sharoiti musoid faroham ovarda meshavad. Mas., baroi gun omadani shigellaho va salmonellaho bulyoni seleniti, ki az seleniti natriyi tursh iborat buda, bahri rushdi in bakteriyaho musoidat mekunad, istifoda megardad.
Muhiti tashkhisi tafriqavi baroi farq kardani mikroorganizmho peshbini shudaast. Bo kumaki on mikroorganizmhoro metavon az rui alomathoi fermentativii judogona farq kard. In guna M. g. indikator dorad, ki hangomi tagyir yoftani pH (binobar hosil shudani mahsuli tajziyai moddaho) rangi muhitro digargun mesozad. CHunonchi, hangomi tashkhisi bemorihoi siroyatii ruda az muhiti Endo istifoda mekunand, ki juzi asosii on agari gushtupeptoni, laktoza va indikator – fuksin meboshad. Muhiti Endo imkon medihad, ki qalamchamikrobhoi ruda (laktozaro bo hosil shudani kislota tajziya mekunand, binobar in koloniyai onho rangi surkh dorad; rangi fuksin) az shigella va salmonellaho (laktozaro tajziya namekunand va koloniyai onho berang ast) farq karda shavad. Baroi omuzishi khosiyati sakharolizii bakteriyaho muhiti Gissro kor mefarmoyand; on dar asosi obi peptoni, yagon karbogidrat (laktoza, mannit va g.) va indikator tahiya karda meshavad. M. g.-i istifodaashon makhsus niz vujud dorand, mas., baroi brutsellaho – muhiti jigari, baroi anaerobho – muhiti Kitt-Tarotsi. Muhiti Ploskirev misli muhiti Endo ast. Muhiti Soton baroi kishti mikrobakteriyahoi sil istifoda meshavad.
M. g.-ro dar laboratoriyaho tayyor mekunand.

S. S. Sattorov.