What kind of year did the 2010-11 Hot 50 have? Who's getting hotter? Who missed out last year but has had a mighty hot year all the same, and merits consideration.

To answer these questions, the Digest has drawn up a company-by-company brief.

1. Amyris. Monster year for yeast-based advanced sugar fermentation into fuels, lubes, chemicals. Customers appearing out of the woodwork. CEO John Melo reportedly buying Brazil, possibly Mars, in the race for capacity. Authors of “One Billion Things to Build Out of Biofene.” Got to Brazil before anyone else. Beloved more by the French (specifically, Total) than Jerry Lewis or Thomas Jefferson. DOE grantee.

2. Solazyme. Oversubscribed IPO (for algae-based) advanced sugar fermentation into renewable oils for fuels, chemicals, personal care and food products. San Francisco is putting another freeway in to handle the Biz Dev traffic. Currently capacity sold out through 2525. Scouring Craigs List for fermenting capacity. Top prospect for a sales call if thou art selling steel, or ground. In Brazil, in France; partnered with Qantas for aviation biofuels. DOE grantee.

3. POET. The Monsters of the Midway. Aimed at 3.5 billion gallons, and these guys don’t mess around. This company is basically China disguised as an ethanol venture. Discount at your peril. DOE grantee, and DOE loan guarantee.

4. LS9. A technology that makes scientists gush and weep. Founded off George Church/Chris Somerville scribble on a napkin. Building a demo in Florida. Seriously snooping around Brazil for the right deal. When will the technology be really, really ready for prime time? If soon, look out, it’s a competitor-killer. DOE grantee.

5. Gevo. Another IPO, high-flyer this year, and bought a Luverne, MN ethanol plant, to switch to isobutanol by June. Makes isobutanol, jet fuel via fermentation of corn starch. Either the single most undervalued stock on NASDAQ, or a 50 million gallon ethanol venture with a $300M market cap. We’ll know by Q1 next year. DOE grantee.

6. DuPont Danisco. Likely to lose the “Danisco” following Dupont/Danisco merger. Don’t take it from us, take it from BP: “The only two companies really getting ready for real scale are BP and Dupont.” Cellulosic ethanol from switchgrass, corn cobs; first commercial plant planned for Iowa. DOE grantee.

7. Novozymes. Aloof but magnificent enzyme developers. Fearsome competitor. Ruthlessly ratcheting down the cellulosic biofuels enzyme costs, down more than half in the past two years. Says cellulosic ethanol is four years away, down from five. Picked up a nice patent infringement win over Danisco. Sales climbing at 3X global GDP.

8. Coskata. Raising money. Open for business. Investors have blanched at the dilutive price of scale-up financing options, so far presented. Major project ready to go in Alabama. Rumors swirling of an imminent acquisition or other strategic shift, if they can’t break through by early 2012. Locking horns with INEOS Bio over trade secrets. USDA loan guarantee.

9. Codexis. Shell, Shell, Shell, Shell, cheap sugar, Shell, Shell, bagasse, Shell and Shell. Buying up IP from Maxygen was a masterstroke. Enzyme developer, based on gene shuffling technology.

10. Sapphire Energy. A Zillion Gallons or Bust. Massive scale, minimizing cost is dictating every choice in their New Mexico build-out. The biggest open pond venture — “if rice works, why not algae”. Collapsing 1,000 years of development into 10 years, can they get there? Serious mojo, man. DOE grantee. USDA loan guarantee.

11. Virent. Pilot done, now going for scale. Everyone’s Fave for the sugar-to-diesel route not using fermentation. Uses a thermochemical process. Expected to develop in Brazil, US. DOE grantee.

12. Mascoma. IPO filed. Massive hope on this one. No one on the outside is quite sure why they haven’t broken through to scale. Would help if Valero hit the accelerator, the way Total did for Amyris. Consolidated bioprocessing of wood to biofuels, chems. Acquired SunOpta pretreatment, now Mascoma Canada. DOE grantee.

13. Ceres. The most serious effort going, by a country mile, in developing switchgrass and energy cane. Salt-tolerance, drought tolerance, nutrient take up, yield improvement on their target list.

14. Cobalt Technologies. Biobutanol’s Street Cred gang – doing their demo now. Big deal in Brazil just went down. It’s n-butanol, more opportunities in chems than isobutanol. Why make a $2 fuel when you make a $5 chemical, sez CEO Rick Wilson. Developing jet fuel for the US Navy.

15. Honeywell’s UOP. The veggie oil to jet fuel upgrading technology of choice. Also partnered with Ensus in Envergent, the pyrolysis venture. DOE grantee.

16. Enerkem. Haley Barbour’s other pet, besides KiOR. Canada’s Garbage+magic play, first commercial in Alberta. Fave of landfill operators. DOE grantee.

17. BP Biofuels. Backward integrating – currently wooing growers from Texas to Brazil. Only interested in world domination. Well on the way. Cellulosic ethanol and biobutanol in US, sugarcane ethanol in Brazil. Theme is “advantaged biofuels” vs “advanced biofuels”. Invested in Qteros, Chromatin.

18. Genencor. Accellerase Trio came out this year. Developing bioisoprene. Launched its open development initiative – think AppStore.  Serious partnering with anyone, everything that needs an enzyme. Watch out on this one, seriously. Dupont paid huge freaking dollars to get a hold of this, they want to get their money out, will be pressing pedal to the metal.

19. Petrobras. Were going medium big on biofuels. President Roussef had a word. Now, going HUGE on biofuels.

20. Abengoa Bioenergy. The Spanish conquistadores. Hugoton, Kansas – cellulosic ethanol from corn stover via enzymatic hydrolysis. Dyadic partner. Now on the fast track. DOE grantee.

21. Qteros. The little biovarmint that could – consolidated bioprocessing on the nanoscale. Hooked up with Praj in India. Investors include BP.