Writing for the search engines specifically is not really practical in business marketing, but there are a number of things you can do which will help – but not conflict with the requirements of writing for humans.
It's not really practical, or even desirable, specifically to write pages for the search engines in business marketing. The average page on your company website about your blue widgets has to work for both prospects and search engines. Fortunately, the days when Google responded positively to the same phrase being included 20 times on a page have long gone. Huge efforts have been put into developing search engine algorithms which respond to the same signals which make a page attractive to real people, and this is going to be increasingly the case in the future.
However, I'd still suggest there are a number of things which you should bear in mind when writing a web page. These shouldn't conflict with the requirements of writing for humans. The first is to start with a target word or phrase. It might be as simple as "blue widgets", if that's what the page is about, but if a simple Google search shows you're competing for that phrase with hundreds of other websites, including Wikipedia, Amazon, etc., then you might like to find more of a "long tail" phrase to summarise the page. It's better to be number 1 in Google for a phrase which gets typed in ten times a month than it is to be number 100 for a phrase which gets typed in dozens of times a day.
So, let's say you've decided that instead of "blue widgets", your page is going to target "fastest blue widget in the UK". You'll include that phrase in your page's title tag, description meta tag and – if you can – in the headline. Should your system allow it, that should be in the page filename (the eventual URL/web address) too. Another place to include it, if possible, is in the title, alt tag and description of the main image on the page.
Now write the page for your prospects, just as you would with any other piece of marketing material. Don't worry about search engines. When you're done, go back and see if you've included the target phrase in the copy. If you've done so without particularly thinking about it, that's great, even if it's included quite a few times. If you haven't, and you can squeeze the phrase in once or twice without making the copy seem too contrived, do take the opportunity to do so. The first and last sentences are always particularly good places. Finally, most search engine experts recommend that you link to the page from elsewhere on your site using the target phrase in the link; and even better, try to obtain links from other sites with the target phrase in their links.
As an example, I've tried to incorporate the points above in this page, using the term 'writing for the search engines'.