生物学英文文献翻译

Question

Studies have indicated that the medium composition and
growth conditions can influence the type and yield of biosur-
factant. Carbon source influences biosurfactant synthesis by
either induction or repression. In some cases addition of
water-immiscible substrates results in induction of biosurfac-
tant production. The induction of sophorolipid synthesis by
addition of long-chain fatty acids, hydrocarbons, or glycerides
to growth media of Torulopsis magnoliae (14), of trehalolipid
synthesis in Rhodococcus erythropolis by addition of hydrocar-bons (15), and of glycolipid-EM (where EM = emulsifier) in
P. aeruginosa SB-30 by addition of alkanes (16) has been re-
ported. Induction also regulates synthesis of many lipopep-
tide biosurfactants (17–19). Banat et al. (20) observed little
biosurfactant production when cells were growing on a read-
ily available carbon source. Only when the soluble carbon was
fully consumed and a water-immiscible hydrocarbon was
available was biosurfactant production triggered. A carbon
source in the medium, particularly a carbohydrate, has con-
siderable bearing on the type of glycolipids formed. Suzuki et
al. (21) observed that glucose, fructose, and sucrose lipids are
formed by Arthrobacter paraffineus and several species of
Corynebacterium, Nocardia, and Brevibacterium during growth
on the corresponding sugar. The Bacillus strain used in this
study is able to utilize glucose, sucrose, and sodium pyruvate
for biosurfactant production. The biosurfactant was not pro-
duced when sodium acetate was used as the carbon source.
The strain was able to utilize n-hexadecane and pristane for
growth but not for biosurfactant production. Sucrose was
found to be a suitable carbon source for maximal growth and
biosurfactant production and was studied at a concentration
of 2% in minimal medium.There is evidence that nitrogen plays an important (defi-
nite) role in the production of surface-active compounds by
microorganisms. Arthrobacter paraffineus ATCC 19558 pre-
ferred ammonium to nitrate for biosurfactant production.
Urea also resulted in good surfactant production (22). An in-
vestigation of rhamnolipid production by Pseudomonas 44Ti
on olive oil showed that sodium nitrate was the best nitrogen
source (23). Syldatk et al. (24) showed that nitrogen limita-
tion increased the production of some biosurfactants but
also changed the composition of the biosurfactants. In the
present study, both sodium nitrate and potassium nitrate are
preferred nitrogen sources. Bacillus subtilis MTCC 2423 was
not able to utilize ammonium sulfate, but exhibited a prefer-
ence for nitrate ions. Potassium nitrate (3g/L) was found to
be optimal for biosurfactant production. The biosurfactant
production was ca.1.0 g/L with urea.
翻译量还是比较大的，专业词汇较多，希望是生物专业的同学能帮帮忙，翻译得好的话有加分。。
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Answer 1

终于翻译完了，人工的哦！无语病，你大可放心！
有研究表明，培养基组成成分和生长条件可以影响生物表面活性剂的种类和产量。碳源通过或诱导或镇压的方法影响生物表面活性剂的合成。在某些情况下增补水混溶基板表面活性剂可以令生物表面活性剂增产。槐糖脂的合成诱导可通过增加长链脂肪酸，碳氢化合物，甘油酯或光滑球拟木兰生长介质达到目的，（14）用在红串红球菌的槐糖脂合成作用中的烃，丝宝（15），和糖脂，在铜绿假单胞菌中添加烷烃等方法来增产的事例（16）已有过报道。生物表面活性剂的增产还约束了许多感应脂肽类生物表面活性剂（17-19）的合成。巴纳特等人（20）观察了的小生物表面活性剂产生，这些细胞很容易获得碳源从而生长。只有当水溶性碳完全消耗，不容于水的碳氢化合物可利用时，生物表面活性剂的生产才被激活。一个来源于分子中的碳，尤其是碳水化合物，对糖脂类型的形成有着相当大的影响。铃木等人（21）观察到，葡萄糖，果糖，蔗糖脂是由石蜡节杆菌和若干种棒状杆菌，诺卡氏菌和短杆菌的生长发育过程中用到的相应的糖组成的。用于这研究中的芽孢杆菌菌株能够利用葡萄糖，蔗糖，生物表面活性剂生产丙酮酸钠。醋酸钠作为碳源时该生物表面活性剂不会产生。该菌株能够利用正十六烷和姥鲛烷来生长，但不能生产生物表面活性剂。蔗糖被发现是一个能提供最大的增长率和生产生物表面活性剂的浓度适当的碳源，并被放在2％的浓度最低的介质中研究。有证据表明，氮（很明显）在由微生物组成的表面活性化合物生产中扮演着重要角色。石蜡节杆菌ATCC 于1955-8以铵为表面活性剂被用以生产硝酸。尿素也对表面活性剂的生产有较好作用（22）。一个关于假单胞菌44Ti生产鼠李糖脂的调查表明，橄榄油硝酸钠是最好的氮源（23）。Syldatk等人（24）说，氮的限制增加了一些生物表面活性剂生产，也改变了生物表面活性剂的组成。硝酸钠和硝酸钾都是首选氮源。枯草芽孢杆菌MTCC 2423无法利用硫酸铵，但表现出了对硝酸根离子的偏爱。硝酸钾（3克/升）被发现是生物表面活性剂生产的最佳选择。用尿素能生产该生物表面活性剂约1.0克/ L。