PNAS无可救药了，这样的烂文章也发……%#￥&#…… - 未名空间MITBBS历史存档

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PNAS无可救药了，这样的烂文章也发……%#￥&#……

PNAS无可救药了，这样的烂文章也发……%#￥&#……# Biology - 生物学

i*i2011-11-30 08:11

1 楼

【以下文字转载自 WBCenter 讨论区】
发信人: tiantian365 (天天爱唱歌), 信区: WBCenter
标题: Music版申请代发活动包子
发信站: BBS 未名空间站 (Mon Oct 1 17:46:54 2012, 美东)
注：1）版面活动：手续费无；2）代发包子：手续费10%:
版面活动
代发版面/ID:
天籁之音(music)/tiantian365
代发事由(主题标题或链接):
筷子猫大婚庆典嘉年华
活动内容贴：
http://www.mitbbs.com/article0/Music/31558715_0.html
活动总结及颁奖典礼贴：
http://www.mitbbs.com/article_t/Music/31604261.html
具体奖励ID及金额如下：
qxqx 50
xlyytchy 50
numi 50
Vieux 50
Aside 50
frankzappa 50
botaoyaya 130（50+40+40）
turkeylin 50
letwave 90（50+40）
jazzcat 90（50+40）
zhangsan 140（50+50+40）
littledreamy 50
Tianma 50
sanduoo 50
SodaBubble 50
supercat123 50
bbppb 50
yangjin 50
tiantian365 50
remotesky 50
muyun7 50
LaziDragon 90（50+40）
GannTrader 90（50+40）
sui 70（50+20）
aising 50
civicex 50
Crazysongs 50
Catccaatt 20
Wiids 20
Cadgn 20
共：1760，请从music版版面小金库支取。
同主题链接：
http://mitbbs.com/article_t/WBCenter/12539437.html

T*s2011-11-30 08:11

2 楼

怎么大家讨论的不是棒子的，就是烂果子的。别家的都不行吗？
棒子的东西我是不会再买的，如果别家的实在不行，难道只能烂果子？

s*s2011-11-30 08:11

3 楼

谁叫人家是名人呢～
http://www.ncbi.nlm.nih.gov/pubmed/22123987
Proc Natl Acad Sci U S A. 2011 Nov 28. [Epub ahead of print]
Synthesis of three advanced biofuels from ionic liquid-pretreated
switchgrass using engineered Escherichia coli.
Bokinsky G, Peralta-Yahya PP, George A, Holmes BM, Steen EJ, Dietrich J,
Soon Lee T, Tullman-Ercek D, Voigt CA, Simmons BA, Keasling JD.
Source
Joint BioEnergy Institute, 5885 Hollis Avenue, Emeryville, CA 94608.
Abstract
One approach to reducing the costs of advanced biofuel production from
cellulosic biomass is to engineer a single microorganism to both digest
plant biomass and produce hydrocarbons that have the properties of
petrochemical fuels. Such an organism would require pathways for hydrocarbon
production and the capacity to secrete sufficient enzymes to efficiently
hydrolyze cellulose and hemicellulose. To demonstrate how one might engineer
and coordinate all of the necessary components for a biomass-degrading,
hydrocarbon-producing microorganism, we engineered a microorganism naï
ve to both processes, Escherichia coli, to grow using both the cellulose and
hemicellulose fractions of several types of plant biomass pretreated with
ionic liquids. Our engineered strains express cellulase, xylanase, beta-
glucosidase, and xylobiosidase enzymes under control of native E. coli
promoters selected to optimize growth on model cellulosic and hemicellulosic
substrates. Furthermore, our strains grow using either the cellulose or
hemicellulose components of ionic liquid-pretreated biomass or on both
components when combined as a coculture. Both cellulolytic and
hemicellulolytic strains were further engineered with three biofuel
synthesis pathways to demonstrate the production of fuel substitutes or
precursors suitable for gasoline, diesel, and jet engines directly from
ionic liquid-treated switchgrass without externally supplied hydrolase
enzymes. This demonstration represents a major advance toward realizing a
consolidated bioprocess. With improvements in both biofuel synthesis
pathways and biomass digestion capabilities, our approach could provide an
economical route to production of advanced biofuels.

z*n2011-11-30 08:11

4 楼

收到! 要去请客了，哈哈。。。

f*i2011-11-30 08:11

5 楼

我有同感
而且不想再用玩安猪了
可能只有上WP7了

I*a2011-11-30 08:11

6 楼

你再悲愤也冒用，

i*i2011-11-30 08:11

7 楼

如需要多退少补的童鞋，请 1）+ 2）。
1）跟帖；
2）给天天或我站内信。

【在 i****i 的大作中提到】

: 【以下文字转载自 WBCenter 讨论区】
: 发信人: tiantian365 (天天爱唱歌), 信区: WBCenter
: 标题: Music版申请代发活动包子
: 发信站: BBS 未名空间站 (Mon Oct 1 17:46:54 2012, 美东)
: 注：1）版面活动：手续费无；2）代发包子：手续费10%:
: 版面活动
: 代发版面/ID:
: 天籁之音(music)/tiantian365
: 代发事由(主题标题或链接):
: 筷子猫大婚庆典嘉年华

b*l2011-11-30 08:11

8 楼

看来不是只有我有这个痛苦

【在 T*******s 的大作中提到】

: 怎么大家讨论的不是棒子的，就是烂果子的。别家的都不行吗？
: 棒子的东西我是不会再买的，如果别家的实在不行，难道只能烂果子？

a*e2011-11-30 08:11

9 楼

发文章能不能尽量不要引PNAS的文章
TAKE PNAS DOWN

【在 s*******s 的大作中提到】

: 谁叫人家是名人呢～
: http://www.ncbi.nlm.nih.gov/pubmed/22123987
: Proc Natl Acad Sci U S A. 2011 Nov 28. [Epub ahead of print]
: Synthesis of three advanced biofuels from ionic liquid-pretreated
: switchgrass using engineered Escherichia coli.
: Bokinsky G, Peralta-Yahya PP, George A, Holmes BM, Steen EJ, Dietrich J,
: Soon Lee T, Tullman-Ercek D, Voigt CA, Simmons BA, Keasling JD.
: Source
: Joint BioEnergy Institute, 5885 Hollis Avenue, Emeryville, CA 94608.
: Abstract

w*w2011-11-30 08:11

10 楼

手续费有点高~~

g*g2011-11-30 08:11

11 楼

华为？

【在 T*******s 的大作中提到】

: 怎么大家讨论的不是棒子的，就是烂果子的。别家的都不行吗？
: 棒子的东西我是不会再买的，如果别家的实在不行，难道只能烂果子？

d*y2011-11-30 08:11

12 楼

吹牛也是要本事的。用这个方法产的biofuel,价值超过了钻石，是一种崭新的方法。

l*e2011-11-30 08:11

13 楼

赞！！

u*r2011-11-30 08:11

14 楼

HTC

b*y2011-11-30 08:11

15 楼

大牛给科普一下。 It seems something interesting and useful (someday). Why 烂
?

O*e2011-11-30 08:11

16 楼

弱弱的问，猜中木有奖么？我就猜抢中偶像火鸡的了，咋整~~

T*s2011-11-30 08:11

17 楼

看来只能等Nokia的WP7了？

【在 f*******i 的大作中提到】

: 我有同感
: 而且不想再用玩安猪了
: 可能只有上WP7了

s*r2011-11-30 08:11

18 楼

小熊，就当这是一份salad。原料和组合都是旧的，就是份量较普通的多了点。即便如
此，原料和酱的处理都有不可取的地方。更关键的是，这salad物廉价高。按这种法门
做下去，biofuels这个行业破产就是早晚。

w*w2011-11-30 08:11

19 楼

还木有发奖么？
已经不记得自己有多少币子了~~

【在 O*******e 的大作中提到】

: 弱弱的问，猜中木有奖么？我就猜抢中偶像火鸡的了，咋整~~

t*g2011-11-30 08:11

20 楼

华为，中兴，很多呀。

【在 T*******s 的大作中提到】

: 怎么大家讨论的不是棒子的，就是烂果子的。别家的都不行吗？
: 棒子的东西我是不会再买的，如果别家的实在不行，难道只能烂果子？

s*s2011-11-30 08:11

21 楼

整篇文章漏洞百出，关键数据大多缺失
IL 处理是 300 rpm强烈搅拌，120度至少 3小时，不知道他要损失多少sugar，看他
substrate loading可以达到5.5%就知道cellulose的DP已经很低了，当然容易降解利用
发酵用试管进行，底物降解率竟然用产物生成量煞有介事地反推，整个过程压根就不知
道到底真正消耗了多少底物
美国人吹牛逼的本事不是盖的，这篇文章名字一搜已经一堆媒体报道了

【在 b******y 的大作中提到】

: 大牛给科普一下。 It seems something interesting and useful (someday). Why 烂
: ?

s*o2011-11-30 08:11

22 楼

赞～～

T*s2011-11-30 08:11

23 楼

HTC那一款？
很多HTC型号一看就是山寨货，而且电池不给力

【在 u***r 的大作中提到】

: HTC

h*r2011-11-30 08:11

24 楼

看看文章的作者中带星号的那位大佬就知道为什么能发了。
还是那句话，悲愤也没有用。
这位大佬接连好几篇所谓的大paper都挺搞笑的～～～
慢慢把一个还有点potential的领域搞死。

T*s2011-11-30 08:11

25 楼

我也想用国货啊，可以你把质量现提高一点行么？

【在 t****g 的大作中提到】

: 华为，中兴，很多呀。

z*h2011-11-30 08:11

26 楼

Most biofuels seemingly "big" papers just cheated laymen.
Example 1. E.J. Steen, Y. Kang, G. Bokinsky, Z. Hu, A. Schirmer, A. McClure,
S.B. del Cardayre, J.D. Keasling, Microbial production of fatty-acid-
derived fuels and chemicals from plant biomass, Nature, 463 (2010) 559-562.
This is a combination of X. Lu, H. Vora, C. Khosla, Overproduction of free
fatty acids in E. coli: Implications for biodiesel production, Metab. Eng.,
10 (2008) 333-339. and a lot of old papers about xylan-utilization.
Example 2: J.E. Dueber, G.C. Wu, G.R. Malmirchegini, T.S. Moon, C.J. Petzold
, A.V. Ullal, K.L.J. Prather, J.D. Keasling, Synthetic protein scaffolds
provide modular control over metabolic flux, Nat. Biotechnol., 27 (2009) 753
-759. It is an extension paper based on L. Bulow, P. Ljungcrantz, K.
Mosbach, Preparation of a soluble bifunctional enzyme by gene fusion, Nat.
Biotechnol., 3 (1985) 821-823 and E.A. Bayer, E. Morag, R. Lamed, The
cellulosome--a treasure-trove for biotechnology, Trends Biotechnol., 12 (
1994) 379-386.
For such big publications, you need cheat or convince editor and ask for
several friends to review it. DONE.

w*a2011-11-30 08:11

27 楼

BlackBerry

【在 T*******s 的大作中提到】

: 怎么大家讨论的不是棒子的，就是烂果子的。别家的都不行吗？
: 棒子的东西我是不会再买的，如果别家的实在不行，难道只能烂果子？

l*12011-11-30 08:11

28 楼

K biofuels方面的工作被您批了很多次了吧?为啥大家都买他帐呢?他那个artemisinic
acid的工作当初吹得那么神乎奇迹最后还是啥都没有发生...
请问作代谢工程的到底哪个方向才是真正赢利,站得住脚的?

McClure,
,
Petzold
753

【在 z*h 的大作中提到】

: Most biofuels seemingly "big" papers just cheated laymen.
: Example 1. E.J. Steen, Y. Kang, G. Bokinsky, Z. Hu, A. Schirmer, A. McClure,
: S.B. del Cardayre, J.D. Keasling, Microbial production of fatty-acid-
: derived fuels and chemicals from plant biomass, Nature, 463 (2010) 559-562.
: This is a combination of X. Lu, H. Vora, C. Khosla, Overproduction of free
: fatty acids in E. coli: Implications for biodiesel production, Metab. Eng.,
: 10 (2008) 333-339. and a lot of old papers about xylan-utilization.
: Example 2: J.E. Dueber, G.C. Wu, G.R. Malmirchegini, T.S. Moon, C.J. Petzold
: , A.V. Ullal, K.L.J. Prather, J.D. Keasling, Synthetic protein scaffolds
: provide modular control over metabolic flux, Nat. Biotechnol., 27 (2009) 753

b*l2011-11-30 08:11

29 楼

我看诺基亚还靠铺一点，至少相机和导航都还好。还不用走流量。

【在 w***a 的大作中提到】

: BlackBerry

s*n2011-11-30 08:11

30 楼

我觉得要求这些做科研的可以盈利是不现实的，倒是一些公司做的metabolic
engineering的项目前景还行，比如DuPont和DSM等。

artemisinic

【在 l*********1 的大作中提到】

: K biofuels方面的工作被您批了很多次了吧?为啥大家都买他帐呢?他那个artemisinic
: acid的工作当初吹得那么神乎奇迹最后还是啥都没有发生...
: 请问作代谢工程的到底哪个方向才是真正赢利,站得住脚的?
:
: McClure,
: ,
: Petzold
: 753

F*k2011-11-30 08:11

31 楼

or moto

j*m2011-11-30 08:11

32 楼

最前沿的科学是在于能还是不能,不是在于值还是不值。
以前不能的东西现在变成能的东西本来就已经很不容易了，要达到真正的实践需要很长
的发展过程。
火车刚发明的时候比马慢多了，而且还要烧大量的燃料，史蒂芬逊估计会被你这种人批
死吧。
楼主的标准实在太高，能做出来的是不是都只有炸药奖得主？
不服这篇的话不如晒晒您的大作？

s*i2011-11-30 08:11

33 楼

等小米吧

o*u2011-11-30 08:11

34 楼

我个人觉得美国的学术界科研资助方式有问题，过于强调概念性和原创性，以及所谓的
好奇心驱动的研究，而忽视了和实用性的衔接，也即applied science或者说
innovation implementation。这方面做的最好的，我认为是日本，欧洲算是其次。
比如在欧洲申请代谢工程的课题，是一定要有dsm,basf这样的大公司的背书的。一个教
授闭门造车的想法，几乎不可能得到资助。项目预申请前，要反复和公司各个部门商讨
，确定可行的研究方向。欧盟基金会在审核的时候，一般会要求公司同时按比例出资（
不一定是现金），证明课题至少是有中期商业价值的，才会资助。
欧洲本来应该是生物燃料研发最迫切的地区，因为欧洲是全世界可能唯一真正有巨大环
保压力的经济体。欧盟很早就定下来，要到某年使用多少多少的生物燃料来替代石油。
但是最初的炒作过去后，欧洲现在的主流代谢工程方向还是高附加值的药物中间体，或
者聚合物单体。现在能实现真正工业化生产并有望盈利的代谢工程途径很多是大学和公
司合作研发的。真正做的改动实际也不多。
但这样的课题在美国大学就很难得到资助，为什么？因为听起来不酷，发不了science/
nature。mit,harvard这样的地方玩点概念是应该的。但整个学界全都去追新求异，而
没有资助去作一些相对琐碎但是非常有用的研究，就有些过了。

【在 j****m 的大作中提到】

: 最前沿的科学是在于能还是不能,不是在于值还是不值。
: 以前不能的东西现在变成能的东西本来就已经很不容易了，要达到真正的实践需要很长
: 的发展过程。
: 火车刚发明的时候比马慢多了，而且还要烧大量的燃料，史蒂芬逊估计会被你这种人批
: 死吧。
: 楼主的标准实在太高，能做出来的是不是都只有炸药奖得主？
: 不服这篇的话不如晒晒您的大作？

T*s2011-11-30 08:11

35 楼

这边能买到吗？

【在 s***i 的大作中提到】

: 等小米吧

s*s2011-11-30 08:11

36 楼

您激动啥啊，好像文章作者是您干爹似的
只能说从众回帖来看，您已经是少数派了
我的标准不高，只能说您的标准太低
把这paper里的水解效率（水解了4天，只水解了6%的cellulose）给真正做水解的牛牛们看看，下巴都要掉下来了～
我的文章就算了吧，估计您也看不懂
当然，这篇文章还是有一些可取之处的，比如，钱多，做了不少东西

【在 j****m 的大作中提到】

x*s2011-11-30 08:11

37 楼

我用lephone，硬件都很好，做工也很精良，只是系统太痛苦了！四叶草可以去死了～
到现在都没有没有大bug的2.3，前置摄像头没法利用

【在 T*******s 的大作中提到】

: 我也想用国货啊，可以你把质量现提高一点行么？

O*e2011-11-30 08:11

38 楼

呵呵，就算它比马慢，但它能拉的东西多啊，这个马比不了

【在 j****m 的大作中提到】

d*32011-11-30 08:11

39 楼

哎，HTC的偏见很多啊。电池现在不是问题了，不厌其烦地拿我的sensation 4G做例子
，买一块1900mA的oem电池，moderate usage可以撑2天！
奇怪为什么HTC入不了大家的法眼呢

B*l2011-11-30 08:11

40 楼

八卦一下，据说这个方向在JK组里已经没有后续工作了。

s*s2011-11-30 08:11

41 楼

发酵四天弄个6%的水解率，想后续都难
这么说吧，产fuel容易，谁都可以做做，弄个“proof-of-concept”
真正的难点和关键在于水解
谁解决了水解，什么fuel都是浮云～
唉，拿这paper跟火车比就有点兴奋点阈值太低了

【在 B*****l 的大作中提到】

: 八卦一下，据说这个方向在JK组里已经没有后续工作了。

h*r2011-11-30 08:11

42 楼

好啊好啊
我们这些苦逼可以检点剩的做了

【在 B*****l 的大作中提到】

: 八卦一下，据说这个方向在JK组里已经没有后续工作了。

z*h2011-11-30 08:11

43 楼

Biofuels R&D is not basic science. You must compete with available systems
and fuels. Keep it in mind, we have enough fossil fuels that can last
another several hundred years. (Check more data, you will know that you are
misled.)
Keasling's work does not equal invention of locomotive. His work may have
great rooms for further improvement. But even his best future cannot compete
with available systems or other systems. It is why his work does not make
sense now or in the future.

z*h2011-11-30 08:11

44 楼

What is vital (and not vital) to advance economically-competitive biofuels
production
http://www.sciencedirect.com/science/article/pii/S1359511311002
Abstract
Since biofuels is a hot topic, many researchers new to this field are eager
to propose different solutions while they often seem not to have full
understanding of the current status of technologies and numerous (hidden)
constraints. As a result, the general public, policymakers, academic
researchers, and industrial developers have been assaulted by a wave of
biased, misinterpreted, or outright false information. In reality, only a
small fraction of exploding biofuels R&D teams are addressing vital rather
than trivial challenges associated with economically production of advanced
biofuels. Biofuels R&D is not a completely basic science project; instead,
it is a typical goal-oriented (engineering) project because so many
constraints prevent economically competitive production of most advanced
biofuels and are expected to do so in the future. In this opinion paper, I
present some basic rules and facts in thermodynamics, physical chemistry,
and special constraints in the transport sector, sort through and challenge
some claimed breakthroughs or new directions, and identify vital topics to
advance biofuels in the short and long terms. Simply speaking, energy
efficiency is the most important long-term criterion whereas cost is the
most important short-term criterion; eventually thermodynamics determines
economics. For light-duty passenger vehicles, which consume ∼60%
transportation fuels, cellulosic ethanol and butanol are the best short- and
middle-term biofuels, whereas sugary hydrogen would be the ultimate biofuel
in the long term. The top three priorities of biofuels R&D are (i) cost-
effective release of sugars from lignocellulose, (ii) co-utilization of
lignocellulose components for the production of value-added compounds that
subsidize whole biorefineries, and (iii) enhancing the biomass-to-kinetic
energy efficiency from conversions to prime movers through a potential
evolutionary scenario from ethanol or butanol/internal combustion engines (
ICE) to ethanol/hybrid diesel-like ICE to sugar hydrogen fuel cell vehicles.

x*u2011-11-30 08:11

45 楼

To Prof. Zhang,
I think you have pointed out the truth. Your paper should go to Current
Opinions in Biotechnology not just Process Biochemistry. I went to the
Electrofuels conference at Providence last month, people in the conference are
talking a lot about biohydrogen and artificial photosynthesis. Non-
cellulosic sugar substrate is a dead end .By the way, Kealsing's fatty acids
project is not the end. One guy (Steven Singer) from JBEI is still working
on this project. Their next step is to engineer the whole Calvin cycle in E
coli and the fixed CO2 in the formate form will be used as carbon source for
biofuel molecule production. OPX, Suncatalytix, Genomatica, Joeul Unlimited
, Ginkgo and major top universities have got tens of millions of funding
from ARPA.E, a divison of DOE.

o*u2011-11-30 08:11

46 楼

非常赞同你的观点。
其实把宝贵的生物质费了死劲的多步转化，最后就是用来做燃料烧掉，听起来就很不靠
谱。能源上，生物燃料一是肯定不够用，最乐观的估计也就是能做点补充，二是长期肯
定竞争不过其他可替代能源。现在还能支撑，无非就是靠政策。
生物质的利用还是应该立足于化工产业对石油的替代。就算五十或者一百年后，大家都
开电动车了。生活的基本品，比如塑料，药品，等等，应该大部分还是碳基的。基础化
工品的供应是风能太阳能或者氢能解决不了的。

are
compete

【在 z*h 的大作中提到】

: Biofuels R&D is not basic science. You must compete with available systems
: and fuels. Keep it in mind, we have enough fossil fuels that can last
: another several hundred years. (Check more data, you will know that you are
: misled.)
: Keasling's work does not equal invention of locomotive. His work may have
: great rooms for further improvement. But even his best future cannot compete
: with available systems or other systems. It is why his work does not make
: sense now or in the future.

z*h2011-11-30 08:11

47 楼

Electrofuel does not work. Joule limited is a joke. It may be worse than
Keasling's process.
Fatty acid esters may work due to unique market that ethanol and hydrogen
cannot work. But it may not compete with more efficiency ways in long terms.
Efficiency,cost and competing technologies.

z*h2011-11-30 08:11

48 楼

Which journal allows me to write my opinion as I like? Only low-level
journals now. After 10 or 20 years, more persons will understand what I am
saying now.

z*h2011-11-30 08:11

49 楼

Biofuels production from biomass would be sufficient to replace most
applications of crude oil. The keys are to increase energy efficiency and
decrease costs.

z*h2011-11-30 08:11

50 楼

Why electrofuel or most solar fuels are dead? Please check that opinion
paper -- conversion of non-point solar energy to point chemical energy is
the most important technological obstacle, which cannot be solved based on
any known technology.
Electricity storage in batteries cannot be scaled up due to physical limits.

L*r2011-11-30 08:11

51 楼

Environment Sci&Tech刚有篇文章说把biomass变成biofuel来减排的效率远不如
直接用biomass烧火取暖

【在 z*h 的大作中提到】

: Biofuels production from biomass would be sufficient to replace most
: applications of crude oil. The keys are to increase energy efficiency and
: decrease costs.

x*u2011-11-30 08:11

52 楼

I will BaiDu your work.
Electrofuels, which aims to engineer the metabolism of autotrophic bacteria
and convet solar/electricity-derived hydrogen, hydrogen sulfide or ammonia
or even electrons into liquid fules by fixing CO2, sounds very cool. That's
why they got tons of fundings from DOE. DOD is also going to launch such
project. The major obstacle is how to improve the CO2 fixation (artifical
photosynthesis) efficiency -- store solar energy in the form of chemical
bond. Photosynthesis efficiency in autotrophic bacteria is way better than
the efficiency in plants.

limits.

【在 z*h 的大作中提到】

: Why electrofuel or most solar fuels are dead? Please check that opinion
: paper -- conversion of non-point solar energy to point chemical energy is
: the most important technological obstacle, which cannot be solved based on
: any known technology.
: Electricity storage in batteries cannot be scaled up due to physical limits.

s*n2011-11-30 08:11

53 楼

Zyh讨论的其实很多人都看到了，但biofuel还是这么热，其实其背后有大量不同的政治
力量在博弈，说到底和美国的政治关系密切，并不是单纯的科研问题了。
还有就是化工产品对于石油总消耗而言只是小头，大概在5-10%，而能源要占到90-95%
，还有就是煤和天然气也是化石能源。

【在 o****u 的大作中提到】

: 非常赞同你的观点。
: 其实把宝贵的生物质费了死劲的多步转化，最后就是用来做燃料烧掉，听起来就很不靠
: 谱。能源上，生物燃料一是肯定不够用，最乐观的估计也就是能做点补充，二是长期肯
: 定竞争不过其他可替代能源。现在还能支撑，无非就是靠政策。
: 生物质的利用还是应该立足于化工产业对石油的替代。就算五十或者一百年后，大家都
: 开电动车了。生活的基本品，比如塑料，药品，等等，应该大部分还是碳基的。基础化
: 工品的供应是风能太阳能或者氢能解决不了的。
:
: are
: compete

s*n2011-11-30 08:11

54 楼

这种完全靠发酵菌株自身产的enzymes来水解biomass，也就是所谓的CBP，现阶段是完
全不现实的。比较现实的做法是用这种菌株（大部分是yeast表达fungal hydrolases）
联合fungi产的cellulases和hemicellulases来水解biomass，理论是可以减少enzyme
loading。
象JK的方向的确不为做工程的人所看重，所有生产biofuel过程的最大瓶颈就是cheap
feedstock，可以是sugars或者是“CO2+light”，后者看似免费，真正利用起来比
biomass还难。

【在 s*******s 的大作中提到】

: 发酵四天弄个6%的水解率，想后续都难
: 这么说吧，产fuel容易，谁都可以做做，弄个“proof-of-concept”
: 真正的难点和关键在于水解
: 谁解决了水解，什么fuel都是浮云～
: 唉，拿这paper跟火车比就有点兴奋点阈值太低了

o*u2011-11-30 08:11

55 楼

生物质用最乐观的估计，也就是能取代20%的石油。
也就是正好差不多能够取代用作化工的石油。
与其用生物质去做燃料，不如用来做更贵的化工品。解放出来的石油，拿去烧掉好了。

【在 s********n 的大作中提到】

: Zyh讨论的其实很多人都看到了，但biofuel还是这么热，其实其背后有大量不同的政治
: 力量在博弈，说到底和美国的政治关系密切，并不是单纯的科研问题了。
: 还有就是化工产品对于石油总消耗而言只是小头，大概在5-10%，而能源要占到90-95%
: ，还有就是煤和天然气也是化石能源。

z*h2011-11-30 08:11

56 楼

That result is not new. In my paper, I pointed it out. The key is that we
need transportation fuels. Only biomass is the major renewable source for
this production. No choice although it is not best compared to burning.
Talk about burning based on economics, no fuel is better than coal. It is
why China is doing.

【在 L*******r 的大作中提到】

: Environment Sci&Tech刚有篇文章说把biomass变成biofuel来减排的效率远不如
: 直接用biomass烧火取暖

z*h2011-11-30 08:11

57 楼

Nearly no electrofuels projects will work based on economical reason. (in
fact, tough scientific obstacles need be solved.) Check prices of
electricity or hydrogen or ammonia as compared to the products, who will
produce cheaper products from costly substrates.
Persons at the DOE National Energy Technology Laboratory laughed at this
project because they are process engineers plus economic analysts. Similar,
DOE officials did not hear opinions from inside, either. As an outside
person, we can criticize some silly research openly.

bacteria

s

【在 x********u 的大作中提到】

: I will BaiDu your work.
: Electrofuels, which aims to engineer the metabolism of autotrophic bacteria
: and convet solar/electricity-derived hydrogen, hydrogen sulfide or ammonia
: or even electrons into liquid fules by fixing CO2, sounds very cool. That's
: why they got tons of fundings from DOE. DOD is also going to launch such
: project. The major obstacle is how to improve the CO2 fixation (artifical
: photosynthesis) efficiency -- store solar energy in the form of chemical
: bond. Photosynthesis efficiency in autotrophic bacteria is way better than
: the efficiency in plants.
:

z*h2011-11-30 08:11

58 楼

Check this paper http://cen.acs.org/articles/89/i47/Sugar-Makers.html
Making ethanol from starch is economically unfavorable. One lb of starch or
sugar costs 30 cents, 1 gallon of ethanol need 11 lbs of feedstock. Ethanol
feedstock cost is 3.3 dollars per gallon, more costly than gasoline.
Considering other expenditure (distillation, lab, capital depreciation), no
one can make money from it. In fact, government provides subsidy to it (to
farmers and manufacturers). On the other side, market of sugars is very
small as compared to gasoline/ethanol.

s*n2011-11-30 08:11

59 楼

根据DoE的能源报告，全世界生物质的产生量是全球能源消耗的10倍，可用来产生能源
而且不与食物冲突的生物质（主要是lignocellulose）大概与全球能源消耗量持平，当
然不同的model得到的结果有出入。
对于高价值的化工产品，对原材料的价格并不sensitive，用一般的glucose或者是生物
质产生的sugar并不是关键；但是对于biofuel而言cheap sugar是关键，只有利用所有
生物质产生的sugar甚至lignin monomers才有可能实现。

【在 o****u 的大作中提到】

: 生物质用最乐观的估计，也就是能取代20%的石油。
: 也就是正好差不多能够取代用作化工的石油。
: 与其用生物质去做燃料，不如用来做更贵的化工品。解放出来的石油，拿去烧掉好了。