菌jun種zhong的de擴kuo大da培pei養yang是shi發fa酵jiao生sheng產chan的de第di一yi道dao工gong序xu,該gai工gong序xu又you稱cheng之zhi為wei種zhong子zi製zhi備bei。種zhong子zi製zhi備bei不bu僅jin要yao使shi菌jun體ti數shu量liang增zeng加jia,更geng重zhong要yao的de是shi,經jing過guo種zhong子zi製zhi備bei培pei養yang出具有高質量的生產種子供發酵生產使用。因此,如何提供發酵產量高、生產性能穩定、數量足夠而且不被其他雜菌汙染的生產菌種,是種子製備工藝的關鍵。
種子擴大培養的任務
工gong業ye生sheng產chan規gui模mo越yue大da,每mei次ci發fa酵jiao所suo需xu的de種zhong子zi就jiu越yue多duo。要yao使shi小xiao小xiao的de微wei生sheng物wu在zai幾ji十shi小xiao時shi的de較jiao短duan時shi間jian內nei,完wan成cheng如ru此ci巨ju大da的de發fa酵jiao轉zhuan化hua任ren務wu,那na就jiu必bi須xu具ju備bei數shu量liang巨ju大da的de微wei生sheng物wu細xi胞bao才cai行xing。菌jun種zhong擴kuo大da培pei養yang的de目mu的de就jiu是shi要yao為wei每mei次ci發fa酵jiao罐guan的de投tou料liao提ti供gong相xiang當dang數shu量liang的de代dai謝xie旺wang盛sheng的de種zhong子zi。因yin為wei發fa酵jiao時shi間jian的de長chang短duan和he接jie種zhong量liang的de大da小xiao有you關guan,接jie種zhong量liang大da,發fa酵jiao時shi間jian則ze短duan。將jiang較jiao多duo數shu量liang的de成cheng熟shu菌jun體ti接jie入ru發fa酵jiao罐guan中zhong,就jiu有you利li於yu縮suo短duan發fa酵jiao時shi間jian,提ti高gao發fa酵jiao罐guan的de利li用yong率lv,並bing且qie也ye有you利li於yu減jian少shao染ran菌jun的de機ji會hui。因yin此ci,種zhong子zi擴kuo大da培pei養yang的de任ren務wu,不bu但dan要yao得de到dao純chun而er壯zhuang的de菌jun體ti,而er且qie還hai要yao獲huo得de活huo力li旺wang盛sheng的de、接(jie)種(zhong)數(shu)量(liang)足(zu)夠(gou)的(de)菌(jun)體(ti)。對(dui)於(yu)不(bu)同(tong)產(chan)品(pin)的(de)發(fa)酵(jiao)過(guo)程(cheng)來(lai)說(shuo),必(bi)須(xu)根(gen)據(ju)菌(jun)種(zhong)生(sheng)長(chang)繁(fan)殖(zhi)速(su)度(du)快(kuai)慢(man)決(jue)定(ding)種(zhong)子(zi)擴(kuo)大(da)培(pei)養(yang)的(de)級(ji)數(shu),抗(kang)生(sheng)素(su)生(sheng)產(chan)中(zhong),放(fang)線(xian)菌(jun)的(de)細(xi)胞(bao)生(sheng)長(chang)繁(fan)殖(zhi)較(jiao)慢(man),常(chang)常(chang)采(cai)用(yong)三(san)級(ji)種(zhong)子(zi)擴(kuo)大(da)培(pei)養(yang)。一(yi)般(ban)50 t發fa酵jiao罐guan多duo采cai用yong三san級ji發fa酵jiao,有you的de甚shen至zhi采cai用yong四si級ji發fa酵jiao,如ru鏈lian黴mei素su生sheng產chan。有you些xie酶mei製zhi劑ji發fa酵jiao生sheng產chan也ye采cai用yong三san級ji發fa酵jiao。而er穀gu氨an酸suan及ji其qi他ta氨an基ji酸suan的de發fa酵jiao所suo采cai用yong的de菌jun種zhong是shi細xi菌jun,生sheng長chang繁fan殖zhi速su度du很hen快kuai,一yi般ban采cai用yong二er級ji發fa酵jiao。
種子製備的過程
細菌、酵母菌的種子製備就是一個細胞數量增加的過程。細菌的斜麵培養基多采用碳源限量而氮源豐富的配方,牛肉膏、蛋白腖常用作有機氮源。細菌培養溫度大多數為37 ℃,少數為28 ℃,細菌菌體培養時間一般1~2天,產芽孢的細菌則需培養5~10天。
黴菌、放線菌的種子製備一般包括兩個過程,即在固體培養基上生產大量孢子的孢子製備和在液體培養基中生產大量菌絲的種子製備過程。
⒈ 孢子製備
孢子製備是種子製備的開始,是發酵生產的一個重要環節。孢子的質量、數量對以後菌絲的生長、繁殖和發酵產量都有明顯的影響。不同菌種的孢子製備工藝有其不同的特點。
⑴ 放線菌孢子的製備 放線菌的孢子培養一般采用瓊脂斜麵培養基,培養基中含有一些適合產孢子的營養成分,如麩皮、豌豆浸汁、蛋白腖和一些無機鹽等。碳源和氮源不要太豐富(碳源約為1%,氮源不超過0.5%),碳tan源yuan豐feng富fu容rong易yi造zao成cheng生sheng理li酸suan性xing的de營ying養yang環huan境jing,不bu利li於yu放fang線xian菌jun孢bao子zi的de形xing成cheng,氮dan源yuan豐feng富fu則ze有you利li於yu菌jun絲si繁fan殖zhi而er不bu利li於yu孢bao子zi形xing成cheng。一yi般ban情qing況kuang下xia,幹gan燥zao和he限xian製zhi營ying養yang可ke直zhi接jie或huo間jian接jie誘you導dao孢bao子zi形xing成cheng。放fang線xian菌jun斜xie麵mian的de培pei養yang溫wen度du大da多duo數shu為wei28 ℃,少數為37 ℃,培養時間為5~14天。
caiyongnayidaidexiemianbaozijieruyetipeiyang,shijunzhongtexingerding。caiyongmuxiemianbaozijieruyetipeiyangjiyouliyufangzhijunzhongbianyi,caiyongzixiemianbaozijieruyetipeiyangjikejieyuejunzhongyongliang。junzhongjinruzhongziguanyouliangzhongfangfa。yizhongweibaozijinguanfa,jijiangxiemianbaozizhichengbaozixuanfuyezhijiejieruzhongziguan。cifangfakejianshaopiyupizhijiandechayi,juyoucaozuofangbian、工藝過程簡單、便(bian)於(yu)控(kong)製(zhi)孢(bao)子(zi)質(zhi)量(liang)等(deng)優(you)點(dian),孢(bao)子(zi)進(jin)罐(guan)法(fa)已(yi)成(cheng)為(wei)發(fa)酵(jiao)生(sheng)產(chan)的(de)一(yi)個(ge)方(fang)向(xiang)。另(ling)一(yi)種(zhong)方(fang)法(fa)為(wei)搖(yao)瓶(ping)菌(jun)絲(si)進(jin)罐(guan)法(fa),適(shi)用(yong)於(yu)某(mou)些(xie)生(sheng)長(chang)發(fa)育(yu)緩(huan)慢(man)的(de)放(fang)線(xian)菌(jun),此(ci)方(fang)法(fa)的(de)優(you)點(dian)是(shi)可(ke)以(yi)縮(suo)短(duan)種(zhong)子(zi)在(zai)種(zhong)子(zi)罐(guan)內(nei)的(de)培(pei)養(yang)時(shi)間(jian)。
⑵ 黴菌孢子的製備 黴菌的孢子培養,一般以大米、小米、玉米、麩皮、麥(mai)粒(li)等(deng)天(tian)然(ran)農(nong)產(chan)品(pin)為(wei)培(pei)養(yang)基(ji)。這(zhe)是(shi)由(you)於(yu)這(zhe)些(xie)農(nong)產(chan)品(pin)中(zhong)的(de)營(ying)養(yang)成(cheng)分(fen)較(jiao)適(shi)合(he)黴(mei)菌(jun)的(de)孢(bao)子(zi)繁(fan)殖(zhi),而(er)且(qie)這(zhe)類(lei)培(pei)養(yang)基(ji)的(de)表(biao)麵(mian)積(ji)較(jiao)大(da),可(ke)獲(huo)得(de)大(da)量(liang)的(de)孢(bao)子(zi)。黴(mei)菌(jun)的(de)培(pei)養(yang)一(yi)般(ban)為(wei)25~28 ℃,培養時間為4~14天。
⒉ 種子製備
種(zhong)子(zi)製(zhi)備(bei)是(shi)將(jiang)固(gu)體(ti)培(pei)養(yang)基(ji)上(shang)培(pei)養(yang)出(chu)的(de)孢(bao)子(zi)或(huo)菌(jun)體(ti)轉(zhuan)入(ru)到(dao)液(ye)體(ti)培(pei)養(yang)基(ji)中(zhong)培(pei)養(yang),使(shi)其(qi)繁(fan)殖(zhi)成(cheng)大(da)量(liang)菌(jun)絲(si)或(huo)菌(jun)體(ti)的(de)過(guo)程(cheng)。種(zhong)子(zi)製(zhi)備(bei)所(suo)使(shi)用(yong)的(de)培(pei)養(yang)基(ji)和(he)其(qi)他(ta)工(gong)藝(yi)條(tiao)件(jian),都(dou)要(yao)有(you)利(li)於(yu)孢(bao)子(zi)發(fa)芽(ya)、菌絲繁殖或菌體增殖。
⑴ 搖瓶種子製備 mouxiebaozifayahejunsifanzhisuduhuanmandejunzhong,xujiangbaozijingyaopingpeiyangchengjunsihouzaijinruzhongziguan,zhejiushiyaopingzhongzi。yaopingxiangdangyuweisuoledezhongziguan,qipeiyangjipeifanghepeiyangtiaojianyuzhongziguanxiangsi。
搖瓶種子進罐,常采用母瓶、子zi瓶ping兩liang級ji培pei養yang,有you時shi母mu瓶ping種zhong子zi也ye可ke以yi直zhi接jie進jin罐guan。種zhong子zi培pei養yang基ji要yao求qiu比bi較jiao豐feng富fu和he完wan全quan,並bing易yi被bei菌jun體ti分fen解jie利li用yong,氮dan源yuan豐feng富fu有you利li於yu菌jun絲si生sheng長chang。原yuan則ze上shang各ge種zhong營ying養yang成cheng分fen不bu宜yi過guo濃nong,子zi瓶ping培pei養yang基ji濃nong度du比bi母mu瓶ping略lve高gao,更geng接jie近jin種zhong子zi罐guan的de培pei養yang基ji配pei方fang。
⑵ 種子罐種子製備 種子罐種子製備的工藝過程,因菌種不同而異,一般可分為一級種子、二級種子和三級種子的製備。孢子(或搖瓶菌絲)beijierudaotijijiaoxiaodezhongziguanzhong,jingpeiyanghouxingchengdaliangdejunsi,zheyangdezhongzichengweiyijizhongzi,bayijizhongzizhuanrufajiaoguanneifajiao,chengweierjifajiao。ruguojiangyijizhongzijierutijijiaodadezhongziguannei,jingguopeiyangxingchenggengduodejunsi,zheyangzhibeidezhongzichengweierjizhongzi,jiangerjizhongzizhuanrufajiaoguanneifajiao,chengweisanjifajiao。tongyangdaoli,shiyongsanjizhongzidefajiao,chengweisijifajiao。
種(zhong)子(zi)罐(guan)的(de)級(ji)數(shu)主(zhu)要(yao)決(jue)定(ding)於(yu)菌(jun)種(zhong)的(de)性(xing)質(zhi)和(he)菌(jun)體(ti)生(sheng)長(chang)速(su)度(du)及(ji)發(fa)酵(jiao)設(she)備(bei)的(de)合(he)理(li)應(ying)用(yong)。種(zhong)子(zi)製(zhi)備(bei)的(de)目(mu)的(de)是(shi)要(yao)形(xing)成(cheng)一(yi)定(ding)數(shu)量(liang)和(he)質(zhi)量(liang)的(de)菌(jun)體(ti)。孢(bao)子(zi)發(fa)芽(ya)和(he)菌(jun)體(ti)開(kai)始(shi)繁(fan)殖(zhi)時(shi),菌(jun)體(ti)量(liang)很(hen)少(shao),在(zai)小(xiao)型(xing)罐(guan)內(nei)即(ji)可(ke)進(jin)行(xing)。發(fa)酵(jiao)的(de)目(mu)的(de)是(shi)獲(huo)得(de)大(da)量(liang)的(de)發(fa)酵(jiao)產(chan)物(wu)。產(chan)物(wu)是(shi)在(zai)菌(jun)體(ti)大(da)量(liang)形(xing)成(cheng)並(bing)達(da)到(dao)一(yi)定(ding)生(sheng)長(chang)階(jie)段(duan)後(hou)形(xing)成(cheng)的(de),需(xu)要(yao)在(zai)大(da)型(xing)發(fa)酵(jiao)罐(guan)內(nei)才(cai)能(neng)進(jin)行(xing)。同(tong)時(shi)若(ruo)幹(gan)發(fa)酵(jiao)產(chan)物(wu)的(de)產(chan)生(sheng)菌(jun),其(qi)不(bu)同(tong)生(sheng)長(chang)階(jie)段(duan)對(dui)營(ying)養(yang)和(he)培(pei)養(yang)條(tiao)件(jian)的(de)要(yao)求(qiu)有(you)差(cha)異(yi)。因(yin)此(ci),將(jiang)兩(liang)個(ge)目(mu)的(de)不(bu)同(tong)、工gong藝yi要yao求qiu有you差cha異yi的de生sheng物wu學xue過guo程cheng放fang在zai一yi個ge大da罐guan內nei進jin行xing,既ji影ying響xiang發fa酵jiao產chan物wu的de產chan量liang,又you會hui造zao成cheng動dong力li和he設she備bei的de浪lang費fei。種zhong子zi罐guan級ji數shu減jian少shao,有you利li於yu生sheng產chan過guo程cheng的de簡jian化hua及ji發fa酵jiao過guo程cheng的de控kong製zhi,可ke以yi減jian少shao因yin種zhong子zi生sheng長chang異yi常chang而er造zao成cheng發fa酵jiao的de波bo動dong。
種子培養
種zhong子zi培pei養yang要yao求qiu一yi定ding量liang的de種zhong子zi,在zai適shi宜yi的de培pei養yang基ji中zhong,控kong製zhi一yi定ding的de培pei養yang條tiao件jian和he培pei養yang方fang法fa,從cong而er保bao證zheng種zhong子zi正zheng常chang生sheng長chang。工gong業ye微wei生sheng物wu培pei養yang法fa分fen為wei靜jing置zhi培pei養yang和he通tong氣qi培pei養yang兩liang大da類lei型xing,靜jing置zhi培pei養yang法fa即ji將jiang培pei養yang基ji盛sheng於yu發fa酵jiao容rong器qi中zhong,在zai接jie種zhong後hou,不bu通tong空kong氣qi進jin行xing培pei養yang。而er通tong氣qi培pei養yang法fa的de生sheng產chan菌jun種zhong以yi需xu氧yang菌jun和he兼jian性xing需xu氧yang菌jun居ju多duo,它ta們men生sheng長chang的de環huan境jing必bi須xu供gong給gei空kong氣qi,以yi維wei持chi一yi定ding的de溶rong解jie氧yang水shui平ping,使shi菌jun體ti迅xun速su生sheng長chang和he發fa酵jiao,又you稱cheng為wei好hao氣qi性xing培pei養yang。
⒈ 表麵培養法
表(biao)麵(mian)培(pei)養(yang)法(fa)是(shi)一(yi)種(zhong)好(hao)氧(yang)靜(jing)置(zhi)培(pei)養(yang)法(fa)。針(zhen)對(dui)容(rong)器(qi)內(nei)培(pei)養(yang)基(ji)物(wu)態(tai)又(you)分(fen)為(wei)液(ye)態(tai)表(biao)麵(mian)培(pei)養(yang)和(he)固(gu)體(ti)表(biao)麵(mian)培(pei)養(yang)。相(xiang)對(dui)於(yu)容(rong)器(qi)內(nei)培(pei)養(yang)基(ji)體(ti)積(ji)而(er)言(yan),表(biao)麵(mian)積(ji)越(yue)大(da),越(yue)易(yi)促(cu)進(jin)氧(yang)氣(qi)由(you)氣(qi)液(ye)界(jie)麵(mian)向(xiang)培(pei)養(yang)基(ji)內(nei)傳(chuan)遞(di)。這(zhe)種(zhong)方(fang)法(fa)菌(jun)的(de)生(sheng)長(chang)速(su)度(du)與(yu)培(pei)養(yang)基(ji)的(de)深(shen)度(du)有(you)關(guan),單(dan)位(wei)體(ti)積(ji)的(de)表(biao)麵(mian)積(ji)越(yue)大(da),生(sheng)長(chang)速(su)度(du)越(yue)快(kuai)。
⒉ 固體培養法
固(gu)體(ti)培(pei)養(yang)又(you)分(fen)為(wei)淺(qian)盤(pan)固(gu)體(ti)培(pei)養(yang)和(he)深(shen)層(ceng)固(gu)體(ti)培(pei)養(yang),統(tong)稱(cheng)為(wei)曲(qu)法(fa)培(pei)養(yang)。它(ta)起(qi)源(yuan)於(yu)我(wo)國(guo)釀(niang)造(zao)生(sheng)產(chan)特(te)有(you)的(de)傳(chuan)統(tong)製(zhi)曲(qu)技(ji)術(shu)。其(qi)最(zui)大(da)特(te)點(dian)是(shi)固(gu)體(ti)曲(qu)的(de)酶(mei)活(huo)力(li)高(gao)。
⒊ 液體深層培養
液ye體ti深shen層ceng種zhong子zi罐guan從cong罐guan底di部bu通tong氣qi,送song入ru的de空kong氣qi由you攪jiao拌ban槳jiang葉ye分fen散san成cheng微wei小xiao氣qi泡pao以yi促cu進jin氧yang的de溶rong解jie。這zhe種zhong由you罐guan底di部bu通tong氣qi攪jiao拌ban的de培pei養yang方fang法fa,相xiang對dui於yu由you氣qi液ye界jie麵mian靠kao自zi然ran擴kuo散san使shi氧yang溶rong解jie的de表biao麵mian培pei養yang法fa來lai講jiang,稱cheng為wei深shen層ceng培pei養yang法fa。其qi特te點dian是shi容rong易yi按an照zhao生sheng產chan菌jun種zhong對dui於yu代dai謝xie的de營ying養yang要yao求qiu以yi及ji不bu同tong生sheng理li時shi期qi的de通tong氣qi、攪拌、溫度與培養基中氫離子濃度等條件,選擇最佳培養條件。
⑴ 深層培養基本操作的三個控製點
① 滅菌 發(fa)酵(jiao)工(gong)業(ye)要(yao)求(qiu)純(chun)培(pei)養(yang),因(yin)此(ci)在(zai)種(zhong)子(zi)培(pei)養(yang)前(qian)必(bi)須(xu)對(dui)培(pei)養(yang)基(ji)進(jin)行(xing)加(jia)熱(re)滅(mie)菌(jun)。所(suo)以(yi)種(zhong)子(zi)罐(guan)具(ju)有(you)蒸(zheng)汽(qi)夾(jia)套(tao),以(yi)便(bian)將(jiang)培(pei)養(yang)基(ji)和(he)種(zhong)子(zi)罐(guan)進(jin)行(xing)加(jia)熱(re)滅(mie)菌(jun),或(huo)者(zhe)將(jiang)培(pei)養(yang)基(ji)由(you)連(lian)續(xu)加(jia)熱(re)滅(mie)菌(jun)器(qi)滅(mie)菌(jun),並(bing)連(lian)續(xu)地(di)輸(shu)送(song)於(yu)種(zhong)子(zi)罐(guan)內(nei)。
② 溫度控製 培pei養yang基ji滅mie菌jun後hou,冷leng卻que至zhi培pei養yang溫wen度du進jin行xing種zhong子zi培pei養yang,由you於yu隨sui著zhe微wei生sheng物wu的de生sheng長chang和he繁fan殖zhi會hui產chan生sheng熱re量liang,攪jiao拌ban也ye會hui產chan生sheng熱re量liang,所suo以yi要yao維wei持chi溫wen度du恒heng定ding,需xu在zai夾jia套tao中zhong或huo盤pan管guan中zhong通tong冷leng卻que水shui循xun環huan。
③ 通氣、攪拌 空(kong)氣(qi)進(jin)入(ru)種(zhong)子(zi)罐(guan)前(qian)先(xian)經(jing)過(guo)空(kong)氣(qi)過(guo)濾(lv)器(qi)除(chu)去(qu)雜(za)菌(jun),製(zhi)成(cheng)無(wu)菌(jun)空(kong)氣(qi),而(er)後(hou)由(you)罐(guan)底(di)部(bu)進(jin)入(ru),再(zai)通(tong)過(guo)攪(jiao)拌(ban)將(jiang)空(kong)氣(qi)分(fen)散(san)成(cheng)微(wei)小(xiao)氣(qi)泡(pao)。為(wei)了(le)延(yan)長(chang)氣(qi)泡(pao)滯(zhi)留(liu)時(shi)間(jian),可(ke)在(zai)罐(guan)內(nei)裝(zhuang)擋(dang)板(ban)產(chan)生(sheng)渦(wo)流(liu)。攪(jiao)拌(ban)的(de)目(mu)的(de)除(chu)增(zeng)加(jia)溶(rong)解(jie)氧(yang)以(yi)外(wai),可(ke)使(shi)培(pei)養(yang)液(ye)中(zhong)的(de)微(wei)生(sheng)物(wu)均(jun)勻(yun)地(di)分(fen)散(san)在(zai)種(zhong)子(zi)罐(guan)內(nei),促(cu)進(jin)熱(re)傳(chuan)遞(di),以(yi)及(ji)pH均充,並使加入的酸和堿均勻分散等。
⑵ 幾種深層培養法
① 控製培養法 根gen據ju罐guan內nei部bu的de變bian化hua情qing況kuang,掌zhang握wo短duan暫zan時shi間jian內nei狀zhuang態tai變bian量liang的de變bian化hua以yi及ji可ke能neng測ce定ding的de環huan境jing因yin子zi對dui微wei生sheng物wu代dai謝xie活huo動dong的de影ying響xiang,並bing以yi此ci為wei基ji礎chu進jin行xing控kong製zhi培pei養yang,以yi達da到dao產chan物wu的de最zui優you培pei養yang條tiao件jian。為wei此ci,用yong測ce定ding狀zhuang態tai變bian量liang的de傳chuan感gan器qi取qu得de數shu據ju,經jing電dian子zi計ji算suan機ji進jin行xing綜zong合he分fen析xi,再zai將jiang其qi結jie果guo作zuo為wei反fan饋kui調tiao節jie的de信xin號hao,將jiang環huan境jing(培養條件)控製於給定的基準內。這就叫做電子計算機控製培養。目前已大量用於露天大罐啤酒發酵。
② 載體培養法 zaitipeiyangfatuotaiyuqufapeiyang,tongshiyouxishouleyetipeiyangdeyoudian,shijinnianlaixinfazhandeyizhongpeiyangfangfa。tezhengshiyitianranhuorengonghechengdeduokongcailiaodaitifupizhileidegutijizhizuoweiweishengwudezaiti,yingyangchengfenkeyiyangekongzhi。fajiaojieshu,zhiyaojiangjuntihepeiyangjijiyachulaijinxingchouti,zaitiyoukeyizhongxinshiyong。
③ 兩步法 在(zai)酶(mei)製(zhi)劑(ji)的(de)兩(liang)步(bu)法(fa)液(ye)體(ti)深(shen)層(ceng)培(pei)養(yang)中(zhong),每(mei)一(yi)步(bu)菌(jun)體(ti)相(xiang)同(tong)而(er)培(pei)養(yang)條(tiao)件(jian)不(bu)同(tong),因(yin)為(wei)微(wei)生(sheng)物(wu)生(sheng)長(chang)與(yu)產(chan)酶(mei)的(de)最(zui)適(shi)條(tiao)件(jian)有(you)很(hen)大(da)的(de)差(cha)異(yi)。例(li)如(ru)往(wang)培(pei)養(yang)基(ji)中(zhong)添(tian)加(jia)葡(pu)萄(tao)糖(tang)能(neng)大(da)大(da)增(zeng)加(jia)菌(jun)體(ti)或(huo)菌(jun)絲(si)的(de)生(sheng)長(chang),然(ran)而(er)卻(que)嚴(yan)重(zhong)阻(zu)礙(ai)許(xu)多(duo)種(zhong)酶(mei)的(de)合(he)成(cheng)。加(jia)強(qiang)培(pei)養(yang)液(ye)的(de)通(tong)氣(qi)雖(sui)然(ran)能(neng)促(cu)進(jin)微(wei)生(sheng)物(wu)的(de)生(sheng)長(chang),可(ke)是(shi)在(zai)多(duo)數(shu)場(chang)合(he)下(xia)反(fan)而(er)抑(yi)製(zhi)酶(mei)的(de)合(he)成(cheng)。為(wei)了(le)取(qu)得(de)最(zui)大(da)的(de)高(gao)活(huo)力(li)酶(mei),必(bi)須(xu)製(zhi)定(ding)一(yi)種(zhong)調(tiao)節(jie)方(fang)法(fa),既(ji)要(yao)求(qiu)細(xi)胞(bao)的(de)單(dan)位(wei)酶(mei)活(huo)力(li)高(gao),又(you)要(yao)求(qiu)細(xi)胞(bao)數(shu)量(liang)多(duo),也(ye)就(jiu)是(shi)說(shuo),給(gei)菌(jun)體(ti)在(zai)各(ge)種(zhong)生(sheng)理(li)時(shi)期(qi)創(chuang)造(zao)不(bu)同(tong)的(de)條(tiao)件(jian)。兩(liang)步(bu)法(fa)液(ye)體(ti)深(shen)層(ceng)培(pei)養(yang)就(jiu)是(shi)實(shi)現(xian)這(zhe)種(zhong)調(tiao)節(jie)的(de)具(ju)體(ti)措(cuo)施(shi)之(zhi)一(yi)。酶(mei)製(zhi)劑(ji)生(sheng)產(chan)兩(liang)步(bu)法(fa)的(de)特(te)點(dian)是(shi)將(jiang)菌(jun)體(ti)生(sheng)長(chang)條(tiao)件(jian)(生長期)與產酶條件(生產期)區(qu)分(fen)開(kai)來(lai)。菌(jun)體(ti)先(xian)在(zai)豐(feng)富(fu)的(de)培(pei)養(yang)基(ji)上(shang)大(da)量(liang)繁(fan)殖(zhi),然(ran)後(hou)收(shou)集(ji)菌(jun)體(ti)濃(nong)縮(suo)物(wu),洗(xi)滌(di)後(hou)再(zai)轉(zhuan)入(ru)添(tian)加(jia)誘(you)導(dao)物(wu)的(de)產(chan)酶(mei)培(pei)養(yang)基(ji),在(zai)此(ci)期(qi)間(jian),菌(jun)體(ti)積(ji)累(lei)大(da)量(liang)的(de)酶(mei),一(yi)般(ban)不(bu)再(zai)繁(fan)殖(zhi),營(ying)養(yang)成(cheng)分(fen)或(huo)誘(you)導(dao)物(wu)得(de)到(dao)充(chong)分(fen)的(de)利(li)用(yong)。
種子質量的控製
種(zhong)子(zi)質(zhi)量(liang)是(shi)影(ying)響(xiang)發(fa)酵(jiao)生(sheng)產(chan)水(shui)平(ping)的(de)重(zhong)要(yao)因(yin)素(su)。種(zhong)子(zi)質(zhi)量(liang)的(de)優(you)劣(lie),主(zhu)要(yao)取(qu)決(jue)於(yu)菌(jun)種(zhong)本(ben)身(shen)的(de)遺(yi)傳(chuan)特(te)性(xing)和(he)培(pei)養(yang)條(tiao)件(jian)兩(liang)個(ge)方(fang)麵(mian)。這(zhe)就(jiu)是(shi)說(shuo)既(ji)要(yao)有(you)優(you)良(liang)的(de)菌(jun)種(zhong),又(you)要(yao)有(you)良(liang)好(hao)的(de)培(pei)養(yang)條(tiao)件(jian)才(cai)能(neng)獲(huo)得(de)高(gao)質(zhi)量(liang)的(de)種(zhong)子(zi)。
㈠ 影響孢子質量的因素及其控製
孢子質量與培養基、培養溫度、濕度、培養時間、接種量等有關,這些因素相互聯係、相互影響,因此必須全麵考慮各種因素,認真加以控製。
⒈ 培養基
構成孢子培養基的原材料,其產地、品種、加工方法和用量對孢子質量都有一定的影響。生產過程中孢子質量不穩定的現象,常常是原材料質量不穩定所造成的。原材料產地、品pin種zhong和he加jia工gong方fang法fa的de不bu同tong,會hui導dao致zhi培pei養yang基ji中zhong的de微wei量liang元yuan素su和he其qi他ta營ying養yang成cheng分fen含han量liang的de變bian化hua。例li如ru,由you於yu生sheng產chan蛋dan白bai腖dong所suo用yong的de原yuan材cai料liao及ji生sheng產chan工gong藝yi的de不bu同tong,蛋dan白bai腖dong的de微wei量liang元yuan素su含han量liang、磷含量、氨(an)基(ji)酸(suan)組(zu)分(fen)均(jun)有(you)所(suo)不(bu)同(tong),而(er)這(zhe)些(xie)營(ying)養(yang)成(cheng)分(fen)對(dui)於(yu)菌(jun)體(ti)生(sheng)長(chang)和(he)孢(bao)子(zi)形(xing)成(cheng)有(you)重(zhong)要(yao)作(zuo)用(yong)。瓊(qiong)脂(zhi)的(de)牌(pai)號(hao)不(bu)同(tong),對(dui)孢(bao)子(zi)質(zhi)量(liang)也(ye)有(you)影(ying)響(xiang),這(zhe)是(shi)由(you)於(yu)不(bu)同(tong)牌(pai)號(hao)的(de)瓊(qiong)脂(zhi)含(han)有(you)不(bu)同(tong)的(de)無(wu)機(ji)離(li)子(zi)造(zao)成(cheng)的(de)。
此外,水質的影響也不能忽視。地區的不同、jijiedebianhuaheshuiyuandewuran,junkechengweishuizhibodongdeyuanyin。weilebimianshuizhibodongduibaozizhiliangdeyingxiang,kezaizhengliushuihuowuyanshuizhongjiarushiliangdewujiyan,gongpeizhipeiyangjishiyong。liruzaipeizhishengchansihuansudexiemianpeiyangjishi,youshizaiwuyanshuineijiaru0.03%(NH4)2HPO4,0.028%KH2PO4及0.01%MgSO4,確保孢子質量,提高四環素發酵產量。
為了保證孢子培養基的質量,斜麵培養基所用的主要原材料,糖、氮、磷lin含han量liang需xu經jing過guo化hua學xue分fen析xi及ji搖yao瓶ping發fa酵jiao試shi驗yan合he格ge後hou才cai能neng使shi用yong。製zhi備bei培pei養yang基ji時shi要yao嚴yan格ge控kong製zhi滅mie菌jun後hou的de培pei養yang基ji質zhi量liang。斜xie麵mian培pei養yang基ji使shi用yong前qian,需xu在zai適shi當dang溫wen度du下xia放fang置zhi一yi定ding的de時shi間jian,使shi斜xie麵mian無wu冷leng凝ning水shui呈cheng現xian,水shui分fen適shi中zhong有you利li於yu孢bao子zi生sheng長chang。
配(pei)製(zhi)孢(bao)子(zi)培(pei)養(yang)基(ji)還(hai)應(ying)該(gai)考(kao)慮(lv)不(bu)同(tong)代(dai)謝(xie)類(lei)型(xing)的(de)菌(jun)落(luo)對(dui)多(duo)種(zhong)氨(an)基(ji)酸(suan)的(de)選(xuan)擇(ze)。菌(jun)種(zhong)在(zai)固(gu)體(ti)培(pei)養(yang)基(ji)上(shang)可(ke)呈(cheng)現(xian)多(duo)種(zhong)不(bu)同(tong)代(dai)謝(xie)類(lei)型(xing)的(de)菌(jun)落(luo),各(ge)種(zhong)氨(an)基(ji)酸(suan)對(dui)菌(jun)落(luo)的(de)表(biao)現(xian)不(bu)同(tong)。氮(dan)源(yuan)品(pin)種(zhong)越(yue)多(duo),出(chu)現(xian)的(de)菌(jun)落(luo)類(lei)型(xing)也(ye)越(yue)多(duo),不(bu)利(li)於(yu)生(sheng)產(chan)的(de)穩(wen)定(ding)。斜(xie)麵(mian)培(pei)養(yang)基(ji)上(shang)用(yong)較(jiao)單(dan)一(yi)的(de)氮(dan)源(yuan),可(ke)抑(yi)製(zhi)某(mou)些(xie)不(bu)正(zheng)常(chang)型(xing)菌(jun)落(luo)的(de)出(chu)現(xian);而對分離篩選的平板培養基則需加入較複雜的氮源,使其多種菌落類型充分表現,以利篩選。因此在製備固體培養基時有兩條經驗:① 供生產用的孢子培養基或作為製備砂土孢子或傳代所用的培養基要用比較單一的氮源,以便保持正常菌落類型的優勢;② 作為選種或分離用的平板培養基,則需采用較複雜的有機氮源,目的是便於選擇特殊代謝的菌落。
⒉ 培養溫度和濕度
weishengwuzaiyigejiaokuandewendufanweineishengchang。danshi,yaohuodegaozhiliangdebaozi,qizuishiwenduqujianhenxiazhai。yibanlaishuo,tigaopeiyangwendu,keshijuntidaixiehuodongjiakuai,suoduanpeiyangshijian,danshi,juntidetangdaixiehedandaixiedegezhongmeilei,duiwendudeminganxingshibutongde。yinci,peiyangwendubutong,jundeshenglizhuangtaiyebutong,ruguobushiyongzuishiwendupeiyangdebaozi,qishengchannenglijiuhuixiajiang。butongdejunzhuyaoqiudezuishiwendubutong,xujingshijiankaochaqueding。liru,guilielianmeijunxiemianzuishiwenduwei36.5~37 ℃,如果高於37 ℃,則孢子成熟早,易老化,接入發酵罐後,就會出現菌絲對糖、氮利用緩慢,氨基氮回升提前,發酵產量降低等現象。培養溫度控製低一些,則有利於孢子的形成。龜裂鏈黴菌斜麵先放在36.5 ℃培養3天,再放在28.5 ℃培養1天,所得的孢子數量比在36.5 ℃培養4天所得的孢子數量增加3~7倍。
斜麵孢子培養時,培養室的相對濕度對孢子形成的速度、數量和質量有很大影響。空氣中相對濕度高時,培養基內的水分蒸發少;相xiang對dui濕shi度du低di時shi,培pei養yang基ji內nei的de水shui分fen蒸zheng發fa多duo。例li如ru,在zai我wo國guo北bei方fang幹gan燥zao地di區qu,冬dong季ji由you於yu氣qi候hou幹gan燥zao,空kong氣qi相xiang對dui濕shi度du偏pian低di,斜xie麵mian培pei養yang基ji內nei的de水shui分fen蒸zheng發fa的de快kuai,致zhi使shi斜xie麵mian下xia部bu含han有you一yi定ding水shui分fen,而er上shang部bu易yi幹gan癟bie,這zhe時shi孢bao子zi長chang得de快kuai,且qie從cong斜xie麵mian下xia部bu向xiang上shang長chang。夏xia季ji時shi空kong氣qi相xiang對dui濕shi度du高gao,斜xie麵mian內nei水shui分fen蒸zheng發fa得de慢man,這zhe時shi斜xie麵mian孢bao子zi從cong上shang部bu往wang下xia長chang,下xia部bu常chang因yin積ji存cun冷leng凝ning水shui,致zhi使shi孢bao子zi生sheng長chang得de慢man或huo孢bao子zi不bu能neng生sheng長chang。試shi驗yan表biao明ming,在zai一yi定ding條tiao件jian下xia培pei養yang斜xie麵mian孢bao子zi時shi,在zai北bei方fang相xiang對dui濕shi度du控kong製zhi在zai40%~45%,而在南方相對濕度控製在35%~42%,所得孢子質量較好。一般來說,真菌對濕度要求偏高,而放線菌對濕度要求偏低。
zaipeiyangxiangpeiyangshi,ruguoxiangduishidupiandi,kefangrushengshuidepingmin,tigaopeiyangxiangneidexiangduishidu,weilebaozhengxinxiankongqidejiaohuan,peiyangxiangmeitianyikaiqijici,yiliyubaozishengchang。xiandaihuadepeiyangxiangshihengwen、恒濕,並可換氣,不用人工控製。
最適培養溫度和濕度是相對的,例如相對濕度、培養基組分不同,對微生物的最適溫度會有影響。培養溫度、培養基組分不同也會影響到微生物培養的最適相對濕度。
⒊ 培養時間和冷藏時間
絲狀菌在斜麵培養基上的生長發育過程可分為五個階段:① 孢子發芽和基內菌絲生長階段;② 氣生菌絲生長階段;③ 孢子形成階段;④ 孢子成熟階段;⑤ 斜麵衰老菌絲自溶階段。
⑴ 孢子的培養時間 基ji內nei菌jun絲si和he氣qi生sheng菌jun絲si內nei部bu的de核he物wu質zhi和he細xi胞bao質zhi處chu於yu流liu動dong狀zhuang態tai,如ru果guo把ba菌jun絲si斷duan開kai,各ge菌jun絲si片pian斷duan之zhi間jian的de內nei容rong是shi不bu同tong的de,有you的de片pian斷duan中zhong含han有you核he粒li,有you的de片pian斷duan中zhong沒mei有you核he粒li,而er核he粒li的de多duo少shao亦yi不bu均jun勻yun,該gai階jie段duan的de菌jun絲si不bu適shi宜yi於yu菌jun種zhong保bao存cun和he傳chuan代dai。而er孢bao子zi本ben身shen是shi一yi個ge獨du立li的de遺yi傳chuan體ti,其qi遺yi傳chuan物wu質zhi比bi較jiao完wan整zheng,因yin此ci孢bao子zi用yong於yu傳chuan代dai和he保bao存cun均jun能neng保bao持chi原yuan始shi菌jun種zhong的de基ji本ben特te征zheng。但dan是shi孢bao子zi本ben身shen亦yi有you年nian輕qing與yu衰shuai老lao的de區qu別bie。一yi般ban來lai說shuo衰shuai老lao的de孢bao子zi不bu如ru年nian輕qing孢bao子zi,因yin為wei衰shuai老lao的de孢bao子zi已yi在zai逐zhu步bu進jin入ru發fa芽ya階jie段duan,核he物wu質zhi趨qu於yu分fen化hua狀zhuang態tai。孢bao子zi的de培pei養yang工gong藝yi一yi般ban選xuan擇ze在zai孢bao子zi成cheng熟shu階jie段duan時shi終zhong止zhi培pei養yang,此ci時shi顯xian微wei鏡jing下xia可ke見jian到dao成cheng串chuan孢bao子zi或huo遊you離li的de分fen散san孢bao子zi,如ru果guo繼ji續xu培pei養yang,則ze進jin入ru斜xie麵mian衰shuai老lao菌jun絲si自zi溶rong階jie段duan,表biao現xian為wei斜xie麵mian外wai觀guan變bian色se、發暗或黃、菌層下陷、有(you)時(shi)出(chu)現(xian)白(bai)色(se)斑(ban)點(dian)或(huo)發(fa)黑(hei)。白(bai)斑(ban)表(biao)示(shi)孢(bao)子(zi)發(fa)芽(ya)長(chang)出(chu)第(di)二(er)代(dai)菌(jun)絲(si),黑(hei)色(se)顯(xian)示(shi)菌(jun)絲(si)自(zi)溶(rong)。孢(bao)子(zi)的(de)培(pei)養(yang)時(shi)間(jian)對(dui)孢(bao)子(zi)質(zhi)量(liang)有(you)重(zhong)要(yao)影(ying)響(xiang),過(guo)於(yu)年(nian)輕(qing)的(de)孢(bao)子(zi)經(jing)不(bu)起(qi)冷(leng)藏(zang),如(ru)土(tu)黴(mei)素(su)菌(jun)種(zhong)斜(xie)麵(mian)培(pei)養(yang)4.5天,孢子尚未完全成熟,冷藏7~8天菌絲即開始自溶。而培養時間延長半天(即培養5天),孢子完全成熟,可冷藏20天也不自溶。過於衰老的孢子會導致生產能力下降,孢子的培養時間應控製在孢子量多、孢子成熟、發酵產量正常的階段終止培養。
⑵ 孢子的冷藏時間 斜xie麵mian孢bao子zi的de冷leng藏zang時shi間jian,對dui孢bao子zi質zhi量liang也ye有you影ying響xiang,其qi影ying響xiang隨sui菌jun種zhong不bu同tong而er異yi,總zong的de原yuan則ze是shi冷leng藏zang時shi間jian宜yi短duan不bu宜yi長chang。曾zeng有you報bao道dao,在zai鏈lian黴mei素su生sheng產chan中zhong,斜xie麵mian孢bao子zi在zai6 ℃冷藏2個月後的發酵單位比冷藏1個月的低18%,冷藏3個月後則降低35%。
⒋ 接種量
zhibeibaozishidejiezhongliangyaoshizhong,jiezhongliangguodahuoguoxiaojunduibaozizhiliangchanshengyingxiang。yinweijiezhongliangdedaxiaoyingxiangdaozaiyidingliangpeiyangjizhongbaozidegetishuliangdeduoshao,jineryingxiangdaojuntideshenglizhuangtai。fanjiezhonghoujunluojunyunfenbuzhenggexiemian,yinyuekefenjunluozheweizhengchangjiezhong。jiezhongliangguoxiaozexiemianshangchangchudejunluoxishu,jiezhongliangguodazexiemianshangjunluomijiyipian。yibanchuandaiyongdexiemianbaoziyaoqiujunluofenbujiaoxi,shiyutiaoxuandangejunluojinxingchuandaipeiyang。jiezhongyaopinghuojinguandexiemianbaozi,yaoqiujunluomidushizhonghuoshaomi,baozishudadaoyaoqiubiaozhun。yibanyizhigaoduwei20 cm、直徑為3 cm的試管斜麵,絲狀菌孢子數要求達到107以上。
接jie入ru種zhong子zi罐guan的de孢bao子zi接jie種zhong量liang對dui發fa酵jiao生sheng產chan也ye有you影ying響xiang。例li如ru,青qing黴mei素su產chan生sheng菌jun之zhi一yi的de球qiu狀zhuang菌jun的de孢bao子zi數shu量liang對dui青qing黴mei素su發fa酵jiao產chan量liang影ying響xiang極ji大da,若ruo孢bao子zi數shu量liang過guo少shao,則ze進jin罐guan後hou長chang出chu的de球qiu狀zhuang體ti過guo大da,影ying響xiang通tong氣qi效xiao果guo;若孢子數量過多,則進罐後不能很好地維持球狀體。
除了以上幾個因素需加以控製之外,要獲得高質量的孢子,還需要對菌種質量加以控製。用各種方法保存的菌種每過1年都應進行1次自然分離,從中選出形態、生產性能好的單菌落接種孢子培養基。製備好的斜麵孢子,要經過搖瓶發酵試驗,合格後才能用於發酵生產。
㈡ 影響種子質量的因素及其控製
種子質量主要受孢子質量、培養基、培養條件、種齡和接種量等因素的影響。搖瓶種子的質量主要以外觀顏色、效價、菌絲濃度或黏度以及糖氮代謝、pH值變化等為指標,符合要求方可進罐。
種子的質量是發酵能否正常進行的重要因素之一。種子製備不僅是要提供一定數量的菌體,更為重要的是要為發酵生產提供適合發酵、具有一定生理狀態的菌體。種子質量的控製,將以此為出發點。
⒈ 培養基
種(zhong)子(zi)培(pei)養(yang)基(ji)的(de)原(yuan)材(cai)料(liao)質(zhi)量(liang)的(de)控(kong)製(zhi)類(lei)似(si)於(yu)孢(bao)子(zi)培(pei)養(yang)基(ji)原(yuan)材(cai)料(liao)質(zhi)量(liang)的(de)控(kong)製(zhi)。種(zhong)子(zi)培(pei)養(yang)基(ji)的(de)營(ying)養(yang)成(cheng)分(fen)應(ying)適(shi)合(he)種(zhong)子(zi)培(pei)養(yang)的(de)需(xu)要(yao),一(yi)般(ban)選(xuan)擇(ze)一(yi)些(xie)有(you)利(li)於(yu)孢(bao)子(zi)發(fa)芽(ya)和(he)菌(jun)絲(si)生(sheng)長(chang)的(de)培(pei)養(yang)基(ji),在(zai)營(ying)養(yang)上(shang)易(yi)於(yu)被(bei)菌(jun)體(ti)直(zhi)接(jie)吸(xi)收(shou)和(he)利(li)用(yong),營(ying)養(yang)成(cheng)分(fen)要(yao)適(shi)當(dang)地(di)豐(feng)富(fu)和(he)完(wan)全(quan),氮(dan)源(yuan)和(he)維(wei)生(sheng)素(su)含(han)量(liang)較(jiao)高(gao),這(zhe)樣(yang)可(ke)以(yi)使(shi)菌(jun)絲(si)粗(cu)壯(zhuang)並(bing)具(ju)有(you)較(jiao)強(qiang)的(de)活(huo)力(li)。另(ling)一(yi)方(fang)麵(mian),培(pei)養(yang)基(ji)的(de)營(ying)養(yang)成(cheng)分(fen)要(yao)盡(jin)可(ke)能(neng)地(di)和(he)發(fa)酵(jiao)培(pei)養(yang)基(ji)接(jie)近(jin),以(yi)適(shi)合(he)發(fa)酵(jiao)的(de)需(xu)要(yao),這(zhe)樣(yang)的(de)種(zhong)子(zi)一(yi)旦(dan)移(yi)入(ru)發(fa)酵(jiao)罐(guan)後(hou)也(ye)能(neng)比(bi)較(jiao)容(rong)易(yi)適(shi)應(ying)發(fa)酵(jiao)罐(guan)的(de)培(pei)養(yang)條(tiao)件(jian)。發(fa)酵(jiao)的(de)目(mu)的(de)是(shi)為(wei)了(le)獲(huo)得(de)盡(jin)可(ke)能(neng)多(duo)的(de)發(fa)酵(jiao)產(chan)物(wu),其(qi)培(pei)養(yang)基(ji)一(yi)般(ban)比(bi)較(jiao)濃(nong),而(er)種(zhong)子(zi)培(pei)養(yang)基(ji)以(yi)略(lve)稀(xi)薄(bo)為(wei)宜(yi)。種(zhong)子(zi)培(pei)養(yang)基(ji)的(de)pH值要比較穩定,以適合菌的生長和發育。pH值的變化會引起各種酶活力的改變,對菌絲形態和代謝途徑影響很大。例如,種子培養基的pH值控製對四環素發酵有顯著影響。
⒉ 培養條件
種zhong子zi培pei養yang應ying選xuan擇ze最zui適shi溫wen度du,前qian麵mian已yi有you敘xu述shu。培pei養yang過guo程cheng中zhong通tong氣qi攪jiao拌ban的de控kong製zhi很hen重zhong要yao,各ge級ji種zhong子zi罐guan或huo者zhe同tong級ji種zhong子zi罐guan的de各ge個ge不bu同tong時shi期qi的de需xu氧yang量liang不bu同tong,應ying區qu別bie控kong製zhi,一yi般ban前qian期qi需xu氧yang量liang較jiao少shao,後hou期qi需xu氧yang量liang較jiao多duo,應ying適shi當dang增zeng大da供gong氧yang量liang。在zai青qing黴mei素su生sheng產chan的de種zhong子zi製zhi備bei過guo程cheng中zhong,充chong足zu的de通tong氣qi量liang可ke以yi提ti高gao種zhong子zi質zhi量liang。例li如ru,將jiang通tong氣qi充chong足zu和he通tong氣qi不bu足zu兩liang種zhong情qing況kuang下xia得de到dao的de種zhong子zi都dou接jie入ru發fa酵jiao罐guan內nei,它ta們men的de發fa酵jiao單dan位wei可ke相xiang差cha1倍。但是,在土黴素發酵生產中,一級種子罐的通氣量小一些卻對發酵有利。通氣攪拌不足可引起菌絲結團、菌(jun)絲(si)粘(zhan)壁(bi)等(deng)異(yi)常(chang)現(xian)象(xiang)。生(sheng)產(chan)過(guo)程(cheng)中(zhong),有(you)時(shi)種(zhong)子(zi)培(pei)養(yang)會(hui)產(chan)生(sheng)大(da)量(liang)泡(pao)沫(mo)而(er)影(ying)響(xiang)正(zheng)常(chang)的(de)通(tong)氣(qi)攪(jiao)拌(ban),此(ci)時(shi)應(ying)嚴(yan)格(ge)控(kong)製(zhi),甚(shen)至(zhi)可(ke)考(kao)慮(lv)改(gai)變(bian)培(pei)養(yang)基(ji)配(pei)方(fang),以(yi)減(jian)少(shao)發(fa)泡(pao)。
對dui青qing黴mei素su生sheng產chan的de小xiao罐guan種zhong子zi,可ke采cai用yong補bu料liao工gong藝yi來lai提ti高gao種zhong子zi質zhi量liang,即ji在zai種zhong子zi罐guan培pei養yang一yi定ding時shi間jian後hou,補bu入ru一yi定ding量liang的de種zhong子zi培pei養yang基ji,結jie果guo種zhong子zi罐guan放fang罐guan體ti積ji增zeng加jia,種zhong子zi質zhi量liang也ye有you所suo提ti高gao,菌jun絲si團tuan明ming顯xian減jian少shao,菌jun絲si內nei積ji蓄xu物wu增zeng多duo,菌jun絲si粗cu壯zhuang,發fa酵jiao單dan位wei增zeng高gao。
⒊ 種齡
種(zhong)子(zi)培(pei)養(yang)時(shi)間(jian)稱(cheng)為(wei)種(zhong)齡(ling)。在(zai)種(zhong)子(zi)罐(guan)內(nei),隨(sui)著(zhe)培(pei)養(yang)時(shi)間(jian)延(yan)長(chang),菌(jun)體(ti)量(liang)逐(zhu)漸(jian)增(zeng)加(jia)。但(dan)是(shi)菌(jun)體(ti)繁(fan)殖(zhi)到(dao)一(yi)定(ding)程(cheng)度(du),由(you)於(yu)營(ying)養(yang)物(wu)質(zhi)消(xiao)耗(hao)和(he)代(dai)謝(xie)產(chan)物(wu)積(ji)累(lei),菌(jun)體(ti)量(liang)不(bu)再(zai)繼(ji)續(xu)增(zeng)加(jia),而(er)是(shi)逐(zhu)漸(jian)趨(qu)於(yu)老(lao)化(hua)。由(you)於(yu)菌(jun)體(ti)在(zai)生(sheng)長(chang)發(fa)育(yu)過(guo)程(cheng)中(zhong),不(bu)同(tong)生(sheng)長(chang)階(jie)段(duan)的(de)菌(jun)體(ti)的(de)生(sheng)理(li)活(huo)性(xing)差(cha)別(bie)很(hen)大(da),接(jie)種(zhong)種(zhong)齡(ling)的(de)控(kong)製(zhi)就(jiu)顯(xian)得(de)非(fei)常(chang)重(zhong)要(yao)。在(zai)工(gong)業(ye)發(fa)酵(jiao)生(sheng)產(chan)中(zhong),一(yi)般(ban)都(dou)選(xuan)在(zai)生(sheng)命(ming)力(li)極(ji)為(wei)旺(wang)盛(sheng)的(de)對(dui)數(shu)生(sheng)長(chang)期(qi),菌(jun)體(ti)量(liang)尚(shang)未(wei)達(da)到(dao)最(zui)高(gao)峰(feng)時(shi)移(yi)種(zhong)。此(ci)時(shi)的(de)種(zhong)子(zi)能(neng)很(hen)快(kuai)適(shi)應(ying)環(huan)境(jing),生(sheng)長(chang)繁(fan)殖(zhi)快(kuai),可(ke)大(da)大(da)縮(suo)短(duan)在(zai)發(fa)酵(jiao)罐(guan)中(zhong)的(de)遲(chi)滯(zhi)期(qi)(調整期),suoduanzaifajiaoguanzhongdefeichanwuhechengshijian,tigaofajiaoguandeliyonglv,jieshengdonglixiaohao。ruguozhonglingkongzhibushidang,zhonglingguoyunianqingdezhongzijierufajiaoguanhou,wangwanghuichuxianqianqishengchanghuanman、泡沫多、發酵周期延長以及因菌體量過少而菌絲結團,引起異常發酵等等;而種齡過老的種子接入發酵罐後,則會因菌體老化而導致生產能力衰退。在土黴素生產中,一級種子的種齡相差2~3 h,轉入發酵罐後,菌體的代謝就會有明顯的差異。
最適種齡因菌種不同而有很大的差異。細菌的種齡一般為7~24 h,黴菌種齡一般為16~50 h,放線菌種齡一般為21~64 h。tongyijunzhongdebutongguanpipeiyangxiangtongdeshijian,dedaodezhongzizhiliangyebuwanquanyizhi,yincizuishidezhonglingyingtongguoduocishiyan,tebieyaogenjubenpizhongzizhilianglaiqueding。
手機版








